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Sample records for field-ion microscope investigations

  1. Field-ion microscope with plasma preparation of specimen surface

    International Nuclear Information System (INIS)

    Suvorov, A.L.; Bobkov, A.F.; Kasatkin, V.A.; Zaitsev, S.V.

    1986-01-01

    This paper presents a method for preparing specimen surfaces for field-ion microscope analysis, in which a brief gas discharge is initiated near the surface under study with simultaneous pulse evaporation by the field of the material of the specimen itself or desorption of foreign atoms and molecular complexes from its surface. The method considerably increases the efficiency of structure analysis of conducting materials in a field-ion microscope. An all-metal field-ion microscope is developed for implementation of the method

  2. Analysis at the atomic level: The atom probe field-ion microscope

    International Nuclear Information System (INIS)

    Miller, M.K.

    1987-01-01

    The atom probe field-ion microscope (APFIM) is a unique analytical instrument that can analyze metals and semiconducting materials on the atomic scale. In recent years, the atom probe has developed into one of the most powerful instruments available for routine microstructural and microchemical analysis of materials. The types of investigations that have been performed have encompassed many diverse metallurgical subjects including phase transformations, segregation, diffusion, catalysis, and radiation damage. 3 refs., 3 figs

  3. Atom-probe field-ion-microscope mass spectrometer

    International Nuclear Information System (INIS)

    Nishikawa, Osamu

    1983-01-01

    The titled analyzer, called simply atom-probe, has been developed by combining a field ion microscope (FIM) and a mass spectrometer, and is divided into the time-of-flight type, magnetic sector type, and quadrupole type depending on the types of mass spectrometers. In this paper, the author first describes on the principle and construction of a high resolution, time-of-flight atom-probe developed and fabricated in his laboratory. The feature of the atom-probe lies in the analysis of atoms and molecules in hyper-fine structure region one by one utilizing the high resolution of FIM. It also has the advantages of directly determining the composition by a ratio of the numbers of respective ions because of a constant detection sensitivity regardless of mass numbers, of the resolution as high as single atom layer in depth direction, and of detecting the positional relationship among detected ions by the order of detection in a sample. To determine the composition in a hyperfine structure region, the limited small number of atoms and molecules in the region must be identified distinctly one by one. In the analyzed result of Ni-silicide formed by heating Si evaporated on a Ni tip at 1000 K for 5 minutes, each isotope was not only clearly separated, but also their abundance ratio was very close to the natural abundance ratio. The second half of the paper reports on the analysis of TiC promising for a cold cathode material, adsorption of CO and alcohol, and the composition and structure of silicides, as a few application examples. (Wakatsuki, Y.)

  4. Atom probe field ion microscope study of the range and diffusivity of helium in tungsten

    International Nuclear Information System (INIS)

    Wagner, A.

    1978-08-01

    A time-of-flight (TOF) atom-probe field-ion microscope (FIM) specifically designed for the study of defects in metals is described. With this automated system 600 TOF min -1 can be recorded and analyzed. Performance tests of the instrument demonstrated that (1) the seven isotopes of molybdenum and the five isotopes of tungsten can be clearly resolved; and (2) the concentration and spatial distribution of all constitutents present at levels greater than 0.05 at. % in a W--25 at. % Re, Mo--1.0 at. % Ti, Mo--1.0 at. % Ti--0.08 at. % Zr (TZM), a low swelling stainless steel (LS1A) and a metallic glass (Metglas 2826) can be measured. The effect of the rate of field evaporation on the quantitative atom probe analysis of a Mo--1.0 at. % Ti alloy and a Mo--1.0 at. % Ti--0.08 at. % Zr alloy was investigated. As the field evaporation rate increased the measured Ti concentration was found to also increase. A simple qualitative model was proposed to explain the observation. The spatial distribution of titanium in a fast neutron irradiated Mo--1.0 at. % Ti alloy has been investigated. No evidence of Ti segregation to the voids was detected nor has any evidence of significant resolution of Ti from the TiC precipitates been detected. A small amount of segregation of carbon to a void was detected

  5. Field-ion microscope studies of the defect structure of the primary state of damage of irradiated metals

    Energy Technology Data Exchange (ETDEWEB)

    Seidman, D. N.

    1975-01-01

    A review is presented of field ion microscope applications in studies of point defect distribution in irradiated metals. FIM results on the primary state of radiation damage in neutron and ion-irradiated iridium and tungsten, at both room-temperature and 78/sup 0/K, showed that it consists of: (1) isolated vacancies; (2) depleted zones; (3) compact vacancy clusters of voids; and (4) dislocation loops. The fraction of vacancies stored in the dislocation loops represented a small fraction of the total vacancy concentration; in the case of tungsten it was approximately 10 percent. These FIM observations provide a simple explanation of the low yield-factor, determined by transmission electron microscopy, for a number of ion-irradiated metals.

  6. Field ion microscopy

    International Nuclear Information System (INIS)

    Ramanathan, D.

    1975-01-01

    The basic features of the Field-Ion Microscope (FIM) and the theory of image formation are explained. Design parameters of the FIM, factors limiting its resolution, interpretation of the image, etc are briefly outlined. Relative merits of the various imaging gases and the applications of the FIM are also covered. (K.B.)

  7. In-situ field-ion microscope study of the recovery behavior of heavy metal ion-irradiated tungsten, tungsten (rhenium) alloys and molybdenum

    International Nuclear Information System (INIS)

    Nielsen, C.H.

    1977-06-01

    Three field ion microscope (FIM) experiments were carried out to study the annealing behavior of heavy ion irradiated tungsten, tungsten (rhenium) alloys and molybdenum. The first experiment dealt with the stage I long-range migration of tungsten self interstitial atoms (SIAs) in high purity tungsten of resistivity ratio, R = 24,000 (R = rho 300 /rho 4 . 2 , where rho 300 and rho 4 . 2 are the room temperature and 0 0 C resistivities). The FIM specimens were irradiated in situ at 18 K with 30 keV W + ions to an average dose of 5 x 10 12 ions cm -2 and subsequently examined by the pulsed-field evaporation technique. The second experiment dealt with the phenomenon of impurity atom trapping of SIAs during long-range migration. It was shown that rhenium atoms in a tungsten matrix tend to capture tungsten SIAs and remain bound up to temperatures as high as 390 K. The final experiment was concerned with the low temperature annealing kinetics of irradiated molybdenum. High purity molybdenum of resistivity ratio R = 5700 was irradiated at 10 K with 30 keV Mo + ions to a dose of approximately 5 x 10 12 ions cm -2 . The results indicated that the electric field has only a minimal effect on the SIA annealing kinetics. This tends to strengthen the contention that the molybdenum SIA becomes mobile at 32 K

  8. Atom-probe field-ion microscopy investigation of CMSX-4 Ni-base superalloy laser beam welds

    International Nuclear Information System (INIS)

    Babu, S.S.; David, S.A.; Vitek, J.M.; Miller, M.K.

    1996-01-01

    CMSX-4 superalloy laser beam welds were investigated by transmission electron microscopy and atom probe field-ion microscopy (APFIM). The weld microstructure consisted of fine (10- to 50-nm) irregularly shaped γ' precipitates (0.65 to 0.75 volume fraction) within the γ matrix. APFIM compositions of the γ and γ' phases were found to be different from those in the base metal. Concentration profiles across the γ and γ' phases showed extensive variations of Cr, Co and Al concentrations as a function of distance within the γ phase. Calculated lattice misfits near the γ/γ' interface in the welds are positive values compared to the negative values for base metal. (orig.)

  9. Study of defects, radiation damage and implanted gases in solids by field-ion and atom-probe microscopy

    International Nuclear Information System (INIS)

    Seidman, D.N.; Amano, J.; Wagner, A.

    1980-10-01

    The ability of the field-ion microscope to image individual atoms has been applied, at Cornell University, to the study of fundamental properties of point defects in irradiated or quenched metals. The capability of the atom probe field-ion microscope to determine the chemistry - that is, the mass-to-charge ratio - of a single ion has been used to investigate the behavior of different implanted species in metals. A brief review is presented of: (1) the basic physical principles of the field-ion and atom-probe microscopes; (2) the many applications of these instruments to the study of defects and radiation damage in solids; and (3) the application of the atom-probe field-ion microscope to the study of the behavior of implanted 3 He and 4 He atoms in tungsten. The paper is heavily referenced so that the reader can pursue his specific research interests in detail

  10. Microscope spectrometer for light scattering investigations.

    Science.gov (United States)

    Barbara, Aude; Lopez-Rios, Tomas; Dumont, Sylvain; Gay, Frédéric; Quémerais, Pascal

    2010-08-01

    We describe a setup including a microscope to study volumes of a few mum(3) by static and dynamic light scattering (DLS) in a backscattering configuration. Light scattered by individual objects of micrometric size can be analyzed in the 400-800?nm spectral range. This setup can also be employed to study both diluted and concentrated colloidal solutions by DLS measurements. For diluted solutions we found evidence of the fluctuations of the number of particles in a confocal volume. We discuss their contribution to the autocorrelation function of the scattered intensity measured as a function of time.

  11. Study of defects and radiation damage in solids by field-ion and atom-probe microscopy

    International Nuclear Information System (INIS)

    Seidman, D.N.

    1979-06-01

    A brief review is presented of: the basic physical principles of the field-ion and atom-probe microscopes; the many applications of these instruments to the study of defects and radiation damage in solids; and the application of the atom-probe field-ion microscope to the study of the behavior of implanted 3 He and 4 He in tungsten

  12. Investigations in high speed blanking: cutting forces and microscopic observations

    Directory of Open Access Journals (Sweden)

    Larue A.

    2010-06-01

    Full Text Available A new hopefull technique, called high speed blanking, has been investigated since few years. To understand the cutting process and how the tools have to be designed, this study is interrested in the cutting force measurement. A new cutting force measurement device has to be designed consider the industrial interest of such a study. The designed test bench induces a calibration process in order to stucy the cutting forces evolution. The paper is discussing the result that the peack load seems to decrease when the punch speed increases. Finally microscopic observations are made in order to find Adiabatic Shear Bands.

  13. Microscopic Investigation of Reversible Nanoscale Surface Size Dependent Protein Conjugation

    Directory of Open Access Journals (Sweden)

    Michael A. Carpenter

    2009-05-01

    Full Text Available Aβ1-40 coated 20 nm gold colloidal nanoparticles exhibit a reversible color change as pH is externally altered between pH 4 and 10. This reversible process may contain important information on the initial reversible step reported for the fibrillogenesis of Aβ (a hallmark of Alzheimer’s disease. We examined this reversible color change by microscopic investigations. AFM images on graphite surfaces revealed the morphology of Aβ aggregates with gold colloids. TEM images clearly demonstrate the correspondence between spectroscopic features and conformational changes of the gold colloid.

  14. Investigating Dissolution and Precipitation Phenomena with a Smartphone Microscope

    Science.gov (United States)

    Lumetta, Gregg J.; Arcia, Edgar

    2016-01-01

    A novel smartphone microscope can be used to observe the dissolution and crystallization of sodium chloride at a microscopic level. Observation of these seemingly simple phenomena through the microscope at 100× magnification can actually reveal some surprising behavior. These experiments offer the opportunity to discuss some basic concepts such as…

  15. Microscopic Investigation of Materials Limitations of Superconducting RF Cavities

    Energy Technology Data Exchange (ETDEWEB)

    Anlage, Steven [Univ. of Maryland, College Park, MD (United States)

    2017-08-04

    Our overall goal is to contribute to the understanding of defects that limit the high accelerating gradient performance of Nb SRF cavities. Our approach is to develop a microscopic connection between materials defects and SRF performance. We developed a near-field microwave microscope to establish this connection. The microscope is based on magnetic hard drive write heads, which are designed to create very strong rf magnetic fields in very small volumes on a surface.

  16. Investigating Dissolution and Precipitation Phenomena with a Smartphone Microscope

    Energy Technology Data Exchange (ETDEWEB)

    Lumetta, Gregg J.; Arcia, Edgar

    2016-10-11

    A novel smartphone microscope can be used to observe the dissolution and crystallization of sodium chloride at a microscopic level. Observation of these seemingly simple phenomena through the microscope at 100× magnification can actually reveal some surprising behavior. These experiments offer the opportunity to discuss some basic concepts such as how the morphological features of the crystals dictates how the dissolution process proceeds, and how materials can be purified by re-crystallization techniques.

  17. MIAMI: Microscope and ion accelerator for materials investigations

    International Nuclear Information System (INIS)

    Hinks, J. A.; Berg, J. A. van den; Donnelly, S. E.

    2011-01-01

    A transmission electron microscope (TEM) with in situ ion irradiation has been built at the University of Salford, U.K. The system consists of a Colutron G-2 ion source connected to a JEOL JEM-2000FX TEM via an in-house designed and constructed ion beam transport system. The ion source can deliver ion energies from 0.5 to 10 keV for singly charged ions and can be floated up to 100 kV to allow acceleration to higher energies. Ion species from H to Xe can be produced for the full range of energies allowing the investigation of implantation with light ions such as helium as well as the effects of displacing irradiation with heavy inert or self-ions. The ability to implant light ions at energies low enough such that they come to rest within the thickness of a TEM sample and to also irradiate with heavier species at energies sufficient to cause large numbers of atomic displacements makes this facility ideally suited to the study of materials for use in nuclear environments. TEM allows the internal microstructure of a sample to be imaged at the nanoscale. By irradiating in situ it is possible to observe the dynamic evolution of radiation damage which can occur during irradiation as a result of competing processes within the system being studied. Furthermore, experimental variables such as temperature can be controlled and maintained throughout both irradiation and observation. This combination of capabilities enables an understanding of the underlying atomistic processes to be gained and thus gives invaluable insights into the fundamental physics governing the response of materials to irradiation. Details of the design and specifications of the MIAMI facility are given along with examples of initial experimental results in silicon and silicon carbide.

  18. The microscopic investigation of structures of moving flux lines by ...

    Indian Academy of Sciences (India)

    of moving flux lines by neutron and muon techniques. E M FORGAN. ∗. , D CHARALAMBOUS and P G KEALEY. School of Physics and Astronomy, University of Birmingham B15 2TT, UK. ∗. Email: emf@thsun7.ph.bham.ac.uk. Abstract. We have used a variety of microscopic techniques to reveal the structure and motion of.

  19. The microscopic investigation of structures of moving flux lines by ...

    Indian Academy of Sciences (India)

    Abstract. We have used a variety of microscopic techniques to reveal the structure and motion of flux line arrangements, when the flux lines in low Tc type II superconductors are caused to move by a transport current. Using small-angle neutron scattering by the flux line lattice (FLL), we are able to demonstrate directly the ...

  20. Microanalysis of welds using field ion microscope/atom probe

    NARCIS (Netherlands)

    Gadgil, V.J.; Kolster, B.H.; Kolster, B.H.

    1994-01-01

    Since transmission electron microscopy (TEM) was first applied to study metals and alloys, an extensive amount of knowledge has been obtained on microstructures that govern the strength, ductility toughness, workability, and other properties of materials. Particularly analytical transmission

  1. Study of defects and radiation damage in solids by field-ion and atom-probe microscopy

    International Nuclear Information System (INIS)

    Seidman, D.N.

    1982-01-01

    An attempt is made to introduce the reader to the basic physical ideas involved in the field-ion and atom-probe field-ion microscope techniques, and to the applications of these techniques to the study of defects and radiation damage in solids. The final section discusses, in precise form, the application of the atom-probe field-ion microscope to the study of the behavior of implanted 3 He and 4 He atoms in tungsten. The paper is heavily referenced so that the reader can pursue his specific research interest in detail

  2. Investigation of Microscopic Materials Limitations of Superconducting RF Cavities

    Energy Technology Data Exchange (ETDEWEB)

    Anlage, Steven [Univ. of Maryland, College Park, MD (United States)

    2014-07-23

    The high-field performance of SRF cavities is often limited by breakdown events below the intrinsic limiting surface fields of Nb, and there is abundant evidence that these breakdown events are localized in space inside the cavity. Also, there is a lack of detailed understanding of the causal links between surface treatments and ultimate RF performance at low temperatures. An understanding of these links would provide a clear roadmap for improvement of SRF cavity performance, and establish a cause-and-effect ‘RF materials science’ of Nb. We propose two specific microscopic approaches to addressing these issues. First is a spatially-resolved local microwave-microscope probe that operates at SRF frequencies and temperatures to discover the microscopic origins of breakdown, and produce quantitative measurements of RF critical fields of coatings and films. Second, RF Laser Scanning Microscopy (LSM) has allowed visualization of RF current flow and sources of nonlinear RF response in superconducting devices with micro-meter spatial resolution. The LSM will be used in conjunction with surface preparation and characterization techniques to create definitive links between physical and chemical processing steps and ultimate cryogenic microwave performance. We propose to develop RF laser scanning microscopy of small-sample Nb pieces to establish surface-processing / RF performance relations through measurement of RF current distributions on micron-length scales and low temperatures.

  3. Pulsed-laser atom-probe field-ion microscopy

    International Nuclear Information System (INIS)

    Kellogg, G.L.; Tsong, T.T.

    1980-01-01

    A time-of-flight atom-probe field-ion microscope has been developed which uses nanosecond laser pulses to field evaporate surface species. The ability to operate an atom-probe without using high-voltage pulses is advantageous for several reasons. The spread in energy arising from the desorption of surface species prior to the voltage pulse attaining its maximum amplitude is eliminated, resulting in increased mass resolution. Semiconductor and insulator samples, for which the electrical resistivity is too high to transmit a short-duration voltage pulse, can be examined using pulsed-laser assisted field desorption. Since the electric field at the surface can be significantly smaller, the dissociation of molecular adsorbates by the field can be reduced or eliminated, permitting well-defined studies of surface chemical reactions. In addition to atom-probe operation, pulsed-laser heating of field emitters can be used to study surface diffusion of adatoms and vacancies over a wide range of temperatures. Examples demonstrating each of these advantages are presented, including the first pulsed-laser atom-probe (PLAP) mass spectra for both metals (W, Mo, Rh) and semiconductors (Si). Molecular hydrogen, which desorbs exclusively as atomic hydrogen in the conventional atom probe, is shown to desorb undissociatively in the PLAP. Field-ion microscope observations of the diffusion and dissociation of atomic clusters, the migration of adatoms, and the formation of vacancies resulting from heating with a 7-ns laser pulse are also presented

  4. A scanning electron microscopic investigation of ceramic orthodontic brackets

    International Nuclear Information System (INIS)

    McDonald, F.; Toms, A.P.

    1990-01-01

    Ceramic brackets were introduced to overcome the esthetic disadvantages of stainless steel brackets. The clinical impression of these brackets is very favorable. However, the sliding mechanics used in the Straightwire (A Company, San Diego, CA, USA) system appear to produce slower tooth movements with ceramic compared to stainless steel brackets. To determine whether this was due to any obvious mechanical problem in the bracket slot, Transcend (Unitek Corporation/3M, Monrovia, CA, USA) ceramic brackets were examined by a scanning electron microscope and compared to stainless steel brackets.Consistently, large surface defects were found in the ceramic bracket slots that were not present in the metal bracket slots. These irregularities could obviously hinder the sliding mechanics of the bracket slot-archwire system and create a greater demand on anchorage. Conversely, the fitting surface of the Transcend ceramic bracket showed extremely smooth surface characteristics, and it would seem advisable for the manufacturers to incorporate this surface within the bracket slot. (author)

  5. Ion trajectories in atom probe field ion microscopy and gas field ion sources

    CERN Document Server

    Castilho, C M C

    1999-01-01

    Trajectories of positive ions produced in a region close to a structured surface, modelled by spherical or spheroidal protrusions and kept at a positive electric potential with respect to a distant screen or detector are calculated. The results are discussed in comparison with similar practical situations produced by field ionization and field evaporation or desorption, such as those occurring in gas field ion sources, field ion microscopy and field desorption spectroscopy. (author)

  6. The sinusoidal lining cells in "normal" human liver. A scanning electron microscopic investigation

    DEFF Research Database (Denmark)

    Horn, T; Henriksen, Jens Henrik Sahl; Christoffersen, P

    1986-01-01

    The scanning electron microscopic was used to study the fenestrations of human liver sinusoids. Thirteen biopsies, where light microscopy and transmission electron microscopy revealed normal sinusoidal architecture, were investigated. The number of fenestrae was calculated in acinar zone 3...

  7. DIY: "Do Imaging Yourself" - Conventional microscopes as powerful tools for in vivo investigation.

    Science.gov (United States)

    Antunes, Maísa Mota; Carvalho, Érika de; Menezes, Gustavo Batista

    2018-01-01

    Intravital imaging has been increasingly employed in cell biology studies and it is becoming one of the most powerful tools for in vivo investigation. Although some protocols can be extremely complex, most intravital imaging procedures can be performed using basic surgery and animal maintenance techniques. More importantly, regular confocal microscopes - the same that are used for imaging immunofluorescence slides - can also acquire high quality intravital images and movies after minor adaptations. Here we propose minimal adaptations in stock microscopes that allow major improvements in different fields of scientific investigation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Complex microscopic express-analysis for biomedical full-scale investigation

    Directory of Open Access Journals (Sweden)

    Datsenko A.M.

    2013-12-01

    Full Text Available To perform biomedical full-scale investigation there had been developed a set of microscopic analysis of histologi-cal preparations. This complex includes cryotome for histological sections, a set of chemical reagents and laboratory glassware for staining, binocular loupes for registration microstructural changes, a microscope with a camera and lighting system on swivel stand, modernized otoscope, a laptop with graphics programs. The complex provides quantitative indicators needed to diagnose the severity and probability estimates of the effect estimation of impacts of extreme factors of different nature.

  9. Moiré method for nanometer instability investigation of scanning hard x-ray microscopes.

    Science.gov (United States)

    Vogt, Ulrich; Köhler, Daniel; Dickmann, Jannis; Rahomäki, Jussi; Parfeniukas, Karolis; Kubsky, Stefan; Alves, Filipe; Langlois, Florent; Engblom, Christer; Stankevič, Tomaš

    2017-05-29

    We present a Moiré method that can be used to investigate positional instabilities in a scanning hard x-ray microscope with nanometer precision. The development of diffraction-limited storage rings offering highly-brilliant synchrotron radiation and improvements of nanofocusing x-ray optics paves the way towards 3D nanotomography with 10 nm resolution or below. However, this trend demands improved designs of x-ray microscope instruments which should offer few-nm beam stabilities with respect to the sample. Our technique can measure the position of optics and sample stage relative to each other in the two directions perpendicular to the beam propagation in a scanning x-ray microscope using simple optical components and visible light. The usefulness of the method was proven by measuring short and long term instabilities of a zone-plate-optics-based prototype microscope. We think it can become an important tool for the characterization of scanning x-ray microscopes, especially prior to experiments with an actual x-ray beam.

  10. Investigation of a magnetic flux-guide for a HTS scanning superconducting quantum interference device microscope

    International Nuclear Information System (INIS)

    Baek, B; Moon, S H; Lee, Su-Young; Lee, S M; Kye, J I; Lee, H J; Khim, Z G

    2004-01-01

    A magnetic flux-guide in the form of a sharp needle is known to enhance the spatial resolution of the scanning SQUID microscope. We investigated the properties of a soft ferromagnetic tip as a flux-guide by measuring the local field of the tip end. The effects of the flux-guide, such as the transmission of a magnetic signal, length dependence, and nonlinear distortion, were observed. We also present the design and construction of a HTS scanning SQUID microscope with a flux-guide and a planar gradiometer. The gradiometer with a flux-guide is an appropriate solution for improving the performance of the scanning SQUID microscope with a flux-guide as regards the prevention of external field noise without magnetic shields

  11. A Transmission Electron Microscope Investigation of Space Weathering Effects in Hayabusa Samples

    Science.gov (United States)

    Keller, Lindsay P.; Berger, Eve L.

    2014-01-01

    The Hayabusa mission to asteroid 25143 Itokawa successfully returned the first direct samples of the regolith from the surface of an asteroid. The Hayabusa samples thus present a special opportunity to directly investigate the evolution of asteroidal surfaces, from the development of the regolith to the study of the more complex effects of space weathering. Here we describe the mineralogy, microstructure and composition of three Hayabusa mission particles using transmission electron microscope (TEM) techniques

  12. Surface characterization of activated chalcopyrite particles via the FLSmidth ROL process. Part 1: Electron microscope investigations

    DEFF Research Database (Denmark)

    Karcz, Adam Paul; Damø, Anne Juul; Illerup, Jytte Boll

    of copper(II) to dope the semiconductor lattice and thereby "activate" the chalcopyrite, thereby reducing leach times below 2 hours (>98% recovery). Because the activation plays a major role in accelerating the leaching step, it is critical to understand the nature of this intermediate and its part...... in the ROL process. The current work presents results from electron microscope investigations of surface-activated particles....

  13. A preliminary investigation: the impact of microscopic condenser on depth of field in cytogenetic imaging

    Science.gov (United States)

    Ren, Liqiang; Qiu, Yuchen; Li, Zheng; Li, Yuhua; Zheng, Bin; Li, Shibo; Chen, Wei R.; Liu, Hong

    2013-02-01

    As one of the important components of optical microscopes, the condenser has a considerable impact on system performance, especially on the depth of field (DOF). DOF is a critical technical feature in cytogenetic imaging that may affect the efficiency and accuracy of clinical diagnosis. The purpose of this study is to investigate the influence of microscopic condenser on DOF using a prototype of transmitted optical microscope, based on objective and subjective evaluations. After the description of the relationship between condenser and objective lens and the theoretical analysis of the condenser impact on system numerical aperture and DOF, a standard resolution pattern and several cytogenetic samples are adopted to assess the condenser impact on DOF, respectively. The experimental results of these objective and subjective evaluations are in agreement with the theoretical analysis and show that, under the specific intermediate range of condenser numerical aperture ( NAcond ), the DOF value decreases with the increase of NAcond . Although the above qualitative results are obtained under the experimental conditions with a specific prototype system, the methods presented in this preliminary investigation could offer useful guidelines for optimizing operational parameters in cytogenetic imaging.

  14. Various Microscopic Methods for Investigating the Venuloid Idioblasts of Pteris grevilleana Wall.

    Directory of Open Access Journals (Sweden)

    Tzu-Tong Kao

    2008-12-01

    Full Text Available Venuloid idioblasts are vein-like structures. In Pteris, they are long epidermal cells with very thick cell walls. In this study, venuloid idioblasts of Pteris grevilleana were investigated with various light microscopic (LM and scanning electron microscopic (SEM techniques and the main purposes of these microscopic techniques are summarized and discussed. To investigate the morphology and distribution of venuloid idioblasts, partial polarization LM technique and cryo-tabletop-SEM technique were used. The idioblasts had lobed margins, acute or round ends, and could be found on both upper and lower epidermis of fertile fronds and sterile fronds. They are distributed on veins, interveinal regions, and leaf margins, but not on costules, costae, and false indusia. By using histochemical staining and SEM with energy dispersive X-ray spectrometer (EDS, it was confirmed that the idioblasts contained silicon. In addition, the venuloid-idioblast-like silica bodies were extracted by wet oxidation method. These indicate that the venuloid indioblast in P. grevilleana is a kind of spicular cell (long epidermal cells containing silica bodies, which are found in Adiantoids and Vittarioids.

  15. Relationship between Microstructure and Properties of Cu-Cr-Ag-(Ce) Alloy Using Microscopic Investigation.

    Science.gov (United States)

    Chen, Huiming; Yuan, Dawei; Wu, Shanjiang; Wang, Hang; Xie, Weibin; Yang, Bin

    2017-01-01

    Microstructure, precipitation hardening response, and mechanical and physical properties of Cu-Cr-Ag alloy and Cu-Cr-Ag-Ce alloy have been investigated using transmission electron microscopy, scanning electron microscope, optical microscope, electrical conductivity analysis, and tensile test. The influence of element Ce on the matrix refinement, impurity removal, and precipitation in the Cu-Cr-Ag alloys has been analyzed. The experimental results show that the strength and electrical conductivity of Ce containing alloys are greater than those of Ce-free alloys after each processing step. Improvement of strength and electrical conductivity of the Cu-Cr-Ag alloy by adding Ce element is attributed to removing oxygen and sulfur from as-cast alloy.

  16. Simultaneous atomic force microscope and quartz crystal microbalance measurements: Investigation of human plasma fibrinogen adsorption

    International Nuclear Information System (INIS)

    Choi, K.-H.; Friedt, J.-M.; Frederix, F.; Campitelli, A.; Borghs, G.

    2002-01-01

    We have combined the tapping-mode atomic force microscope (AFM) and quartz crystal microbalance (QCM) for simultaneous investigation of human plasma fibrinogen adsorption on a metallic surface using these two instruments. The AFM images show the surface changes with molecular resolution while the corresponding resonance frequency shift of the QCM provides quantitative adsorbed mass estimates over the whole sensing area. The combination of AFM with QCM allowing the simultaneous measurements with two techniques working at very different scales and probing different properties of the adsorbed layer provides quantitative and qualitative information that can distinguish different protein adsorption mechanisms

  17. Nanosecond time-resolved investigations using the in situ of dynamic transmission electron microscope (DTEM)

    International Nuclear Information System (INIS)

    LaGrange, Thomas; Campbell, Geoffrey H.; Reed, B.W.; Taheri, Mitra; Pesavento, J. Bradley; Kim, Judy S.; Browning, Nigel D.

    2008-01-01

    Most biological processes, chemical reactions and materials dynamics occur at rates much faster than can be captured with standard video rate acquisition methods in transmission electron microscopes (TEM). Thus, there is a need to increase the temporal resolution in order to capture and understand salient features of these rapid materials processes. This paper details the development of a high-time resolution dynamic transmission electron microscope (DTEM) that captures dynamics in materials with nanosecond time resolution. The current DTEM performance, having a spatial resolution <10 nm for single-shot imaging using 15 ns electron pulses, will be discussed in the context of experimental investigations in solid state reactions of NiAl reactive multilayer films, the study of martensitic transformations in nanocrystalline Ti and the catalytic growth of Si nanowires. In addition, this paper will address the technical issues involved with high current, electron pulse operation and the near-term improvements to the electron optics, which will greatly improve the signal and spatial resolutions, and to the laser system, which will allow tailored specimen and photocathode drive conditions

  18. In situ environmental transmission electron microscope investigation of NiGa nanoparticle synthesis

    DEFF Research Database (Denmark)

    Damsgaard, Christian Danvad; Duchstein, Linus Daniel Leonhard; Elkjær, Christian Fink

    2011-01-01

    detailed Environmental Transmission Electron Microscope (ETEM) investigations of synthesis of NiGa nanoparticles on a thin film support. Samples were prepared by dissolving Ni(NO3)2 and Ga(NO3)3 in a Ni:Ga ratio of 5:3 in millipore water. The solution was subsequently dispersed on transmission electron...... have predicted a nickel gallium alloy to be active for this reaction [1]. NiGa catalysts prepared by incipient wetness impregnation on a high surface area silica support (Saint-Gobain NorPro), using a solution of nickel and gallium nitrates have shown very promising results [2]. This work presents...... microscope (TEM) sample grids. The sample grid was then mounted in a TEM heating holder and inserted in a FEI Titan ETEM with imaging Cs corrector as well as facilities for in situ gas reactions [3]. The ETEM was operated at 300 kV. The synthesis was performed in situ in a H2 flow of 2 Nml/min at a pressure...

  19. Dual investigation of methanogenic processes by quantitative PCR and quantitative microscopic fingerprinting.

    Science.gov (United States)

    Kim, Yong Sung; Westerholm, Maria; Scherer, Paul

    2014-11-01

    Monitoring of methanogenic communities in anaerobic digesters using molecular-based methods is very attractive but can be cost-intensive. A new and fast quantification method by microscopic image analysis was developed to accompany molecular-based methods. This digitalized method, called quantitative microscopic fingerprinting (QMF), enables quantification of active methanogenic cells (N mL(-1)) by their characteristic auto-fluorescence based on coenzyme F420 . QMF was applied to analyze the methanogenic communities in three biogas plant samples, and the results were compared with the relative proportion of gene copy numbers obtained with the quantitative PCR (qPCR). Analysis of QMF demonstrated dominance of Methanomicrobiales and Methanobacteriales in relation to the total methanogenic community in digesters operating at high ammonia concentrations, which corresponded to the results established by qPCR. Absolute microbial counts by QMF and the numbers obtained by qPCR were not always comparable. On the other hand, the restricted morphological analysis by QMF was enhanced by the capability of qPCR to identify microbes. Consequently, dual investigations of both methods are proposed to improve monitoring of anaerobic digesters. For a rough estimation of the methanogenic composition in anaerobic digesters, the QMF method seems to be a promising approach for the rapid detection of microbial changes. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  20. Microscopic investigation of RF surfaces of 3 GHz niobium accelerator cavities following RF processing

    International Nuclear Information System (INIS)

    Graber, J.; Barnes, P.; Flynn, T.; Kirchgessner, J.; Knobloch, J.; Moffat, D.; Muller, H.; Padamsee, H.; Sears, J.

    1993-01-01

    RF processing of Superconducting accelerating cavities is achieved through a change in the electron field emission (FE) characteristics of the RF surface. The authors have examined the RF surfaces of several single-cell 3 GHz cavities, following RF processing, in a Scanning Electron Microscope (SEM). The RF processing sessions included both High Peak Power (P ≤ 50 kW) pulsed processing, and low power (≤ 20 W) continuous wave processing. The experimental apparatus also included a thermometer array on the cavity outer wall, allowing temperature maps to characterize the emission before and after RF processing gains. Multiple sites have been located in cavities which showed improvements in cavity behavior due to RF processing. Several SEM-located sites can be correlated with changes in thermometer signals, indicating a direct relationship between the surface site and emission reduction due to RF processing. Information gained from the SEM investigations and thermometry are used to enhance the theoretical model of RF processing

  1. Microscopic and Spectroscopic Investigation of Poly(3-hexylthiophene Interaction with Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Maurizio De Crescenzi

    2011-08-01

    Full Text Available The inclusion of carbon nanotubes in polymer matrix has been proposed to enhance the polymer’s physical and electrical properties. In this study, microscopic and spectroscopic techniques are used to investigate the interaction between poly(3-hexylthiophene (P3HT and nanotubes and the reciprocal modification of physical properties. The presence of P3HT-covered nanotubes dispersed in the polymer matrix has been observed by atomic force microscopy and transmission electron microscopy. Then, the modification of P3HT optical properties due to nanotube inclusion has been evidenced with spectroscopic techniques like absorption and Raman spectroscopy. The study is completed with detailed nanoscale analysis by scanning probe techniques. The ordered self assembly of polymer adhering on the nanotube is unveiled by showing an example of helical wrapping of P3HT. Scanning tunneling spectroscopy study provides information on the electronic structure of nanotube-polymer assembly, revealing the charge transfer from P3HT to the nanotube.

  2. Investigation of nucleon-induced reactions in the Fermi energy domain within the microscopic DYWAN model

    Energy Technology Data Exchange (ETDEWEB)

    Sebille, F.; Bonilla, C. [SUBATECH, Universite de Nantes, CNRS/IN2P3, 44 - Nantes (France); Blideanu, V.; Lecolley, J.F. [Laboratoire de Physique Corpusculaire, ENSICAEN, Universite de Caen, IN2P3-CNRS, 14 - Caen (France)

    2004-06-01

    A microscopic investigation of nucleon-induced reactions is addressed within the DYWAN model, which is based on the projection methods of out of equilibrium statistical physics and on the mathematical theory of wavelets. Due to a strongly compressed representation of the fermionic wave-functions, the numerical simulations of the nucleon transport in target are therefore able to preserve the quantum nature of the colliding system, as well as a least biased many-body information needed to keep track of the cluster formation. A special attention is devoted to the fingerprints of the phase space topology induced by the fluctuations of the self-consistent mean-field. Comparisons be ween theoretical results and experimental data point out that ETDHF type approaches are well suited to describe reaction mechanisms in the Fermi energy domain. The observed sensitivity to physical effects shows that the nucleon-induced reactions provide a valuable probe of the nuclear interaction in this range of energy. (authors)

  3. Developments of saddle field ion sources and their applications

    International Nuclear Information System (INIS)

    Abdelrahman, M.M.; Helal, A.G.

    2009-01-01

    Ion sources should have different performance parameters according to the various applications for which they are used, ranging from ion beam production to high energy ion implanters. There are many kinds of ion sources, which produce different ion beams with different characteristics. This paper deals with the developments and applications of some saddle field ion sources which were designed and constructed in our lab. Theory of operation and types of saddle field ion sources are discussed in details. Some experimental results are given. The saddle field ion sources operate at low gas pressure and require neither magnetic field nor filament. This type of ion sources is used for many different applications as ion beam machining, sputtering, cleaning and profiling for surface analysis etc

  4. Sedimentological Investigations of the Martian Surface using the Mars 2001 Robotic Arm Camera and MECA Optical Microscope

    Science.gov (United States)

    Rice, J. W., Jr.; Smith, P. H.; Marshall, J. R.

    1999-01-01

    The first microscopic sedimentological studies of the Martian surface will commence with the landing of the Mars Polar Lander (MPL) December 3, 1999. The Robotic Arm Camera (RAC) has a resolution of 25 um/p which will permit detailed micromorphological analysis of surface and subsurface materials. The Robotic Ann will be able to dig up to 50 cm below the surface. The walls of the trench will also be inspected by RAC to look for evidence of stratigraphic and / or sedimentological relationships. The 2001 Mars Lander will build upon and expand the sedimentological research begun by the RAC on MPL. This will be accomplished by: (1) Macroscopic (dm to cm): Descent Imager, Pancam, RAC; (2) Microscopic (mm to um RAC, MECA Optical Microscope (Figure 2), AFM This paper will focus on investigations that can be conducted by the RAC and MECA Optical Microscope.

  5. The investigation of relativistic microscopic optical potential based on RBBG equation

    International Nuclear Information System (INIS)

    Chen Baoqiu; Ma Zhongyu

    1992-01-01

    The relativistic microscopic optical potential is derived from the RBBG equation. The nucleon complex effective mass is determined phenomenologically by a fit to 200 MeV proton-nucleus scattering data. Then the relativistic microscopic optical potentials of proton scattered from different targets: 16 O, 40 Ca, 90 Zr and 208 Pb in the energies range from 160 to 800 MeV have been got. The relativistic microscopic optical potentials have been used to study proton- 40 Ca scattering at 200 MeV. Theoretical predictions for cross section and spin observables are compared with experimental data and phenomenological Dirac optical potential

  6. Microscopic investigations of the terahertz and the extreme nonlinear optical response of semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Golde, Daniel

    2010-06-22

    In the major part of this Thesis, we discuss the linear THz response of semiconductor nanostructures based on a microscopic theory. Here, two different problems are investigated: intersubband transitions in optically excited quantum wells and the THz plasma response of two-dimensional systems. In the latter case, we analyze the response of correlated electron and electron-hole plasmas. Extracting the plasma frequency from the linear response, we find significant deviations from the commonly accepted two-dimensional plasma frequency. Besides analyzing the pure plasma response, we also consider an intermediate regime where the response of the electron-hole plasma consists of a mixture of plasma contributions and excitonic transitions. A quantitative experiment-theory comparison provides novel insights into the behavior of the system at the transition from one regime to the other. The discussion of the intersubband transitions mainly focuses on the coherent superposition of the responses from true THz transitions and the ponderomotively accelerated carriers. We present a simple method to directly identify ponderomotive effects in the linear THz response. Apart from that, the excitonic contributions to intersubband transitions are investigated. The last part of the present Thesis deals with a completely different regime. Here, the extreme nonlinear optical response of low-dimensional semiconductor structures is discussed. Formally, extreme nonlinear optics describes the regime of light-matter interaction where the exciting field is strong enough such that the Rabi frequency is comparable to or larger than the characteristic transition frequency of the investigated system. Here, the Rabi frequency is given by the product of the electrical field strength and the dipole-matrix element of the respective transition. Theoretical investigations have predicted a large number of novel nonlinear effects arising for such strong excitations. Some of them have been observed in

  7. A novel high temperature scanning tunneling microscope for investigating semiconductor surfaces

    Science.gov (United States)

    Lamb, Mark Alan

    2001-11-01

    The issues concerning the description of structural and dynamic features at the nanometer scale has become an active field of research in surface science. The development of the scanning tunneling microscope (STM) has begun only recently to contribute substantially in this effort. For this dissertation project, the author has designed, constructed, and utilized a high temperature ultra high vacuum STM (HT-UHV-STM) for investigating semiconducting surfaces from room temperature to 790°C. In order to isolate the instrument from external noise, the author has developed and demonstrated a novel method of approaching decoupled passive magnetic levitation for vibration isolation. Using advanced magnet technology currently available, this isolation method could achieve resonance frequencies as low as 10-3 Hz for levitation pressures as high as several MPa in a single stage. The instrument has been used to study the clean Si(111) surface at high temperatures. The electromigration phenomenon has been utilized to modify the surface steps and produce metastable reconstruction zones of the "1 x 1" phase and 5 x 5 islands. The growth of the thermodynamically favored 7 x 7 reconstruction has been observed at high temperatures within these metastable phases. The production of nanostructures on the surface by the tip of the STM has been achieved and their thermal relaxation observed and analyzed. Several new observations include the appearance of periodic oscillations in the number of Si atoms constituting each of a pair of 5 x 5 magic islands, imaging of local melting and apparent sputtering of the surface by the tip, and the spontaneous formation of clusters by heat treatment.

  8. An electron microscopic investigation into the possible source of new muscle fibres in teleost fish.

    Science.gov (United States)

    Stoiber, W; Sänger, A M

    1996-12-01

    This study is based on transmission electron microscopic (TEM) investigations of deep (fast, 'white') teleost fish muscle proliferation in early developmental stages of three European cyprinid species and the rainbow trout. Our fine structural findings provide evidence that early myotomal growth in these animals may utilize different mechanisms that are activated in close succession during early life history. First, initial enlargement of the deep muscle bulk in the embryo seems to be due to hypertrophy of the somite-cell derived stock of muscle fibres. Second, we suggest that deep muscle growth becomes additionally powered by attachment of presumptive myogenic cells that originate from and proliferate within the adjacent mesenchymal tissue lining. Third, mesenchyme-derived muscle cell precursors are thought to enter the myotomes via the myosepta. After migration between the pre-established muscle fibres these cells may function as myosatellite cells, thus at least partly providing the stem cell population for subsequent rapid hyperplastic growth. Finally, there is evidence that presumptive deep muscle satellite cells also proliferate by mitotic division in situ. A similar process of myogenic cell migration and proliferation may foster intermediate fibre differentiation. The model of myogenic cell migration is discussed in view of in vitro and in vivo data on satellite cell migratory power and with respect to temperature-induced and species dependent differences. As for the latter, our results indicate that patterns of muscle differentiation may diverge between a fast growing salmonid species and a moderately growing cyprinid species of similar final size. The model is compatible with the well-established idea that teleost muscle growth may rely on different subclasses of myosatellite cells.

  9. Investigating the Microscopic Location of Trace Elements in High-Alpine Glacier Ice

    Science.gov (United States)

    Avak, Sven Erik; Birrer, Mario; Laurent, Oscar; Guillong, Marcel; Wälle, Markus; Jenk, Theo Manuel; Bartels-Rausch, Thorsten; Schwikowski, Margit; Eichler, Anja

    2017-04-01

    Past changes in atmospheric pollution can be reconstructed from high-alpine ice core trace element records (Schwikowski et al., 2004). Percolation of meltwater alters the information originally stored in these environmental archives. Eichler et al. (2001) suggested that the preservation of major ions with respect to meltwater percolation depends on their location in the crystal ice lattice, i.e. grain boundaries versus grain interiors. Other studies have also focused on the effect of meltwater on organic pollutant concentrations as well as on stable isotope profiles in ice cores, whereas no information exists about trace elements. Here, we investigate for the first time the effect of the microscopic location of anthropogenic, dust and volcanic related trace elements on the behavior during meltwater percolation by using two different approaches. On the one hand we assess the microscopic location of trace elements indirectly by analyzing trace element concentrations in a high-alpine ice core, which has been shown to be affected by an inflow of meltwater, using discrete inductively coupled plasma mass spectrometry (ICP-MS). Impurities located at grain boundaries are prone to be removed by meltwater and tend to be depleted in the affected section of the record whereas those incorporated into the ice interior are preserved and not disturbed in the record. In the second approach we work towards a direct quantification of differences in concentrations of trace elements between ice grain boundaries and grain interiors in samples both from unaffected and affected sections of this ice core. Therefore we use cryocell laser ablation (LA) ICP-MS, which is the method of choice for the direct in situ chemical analysis of trace elements at a sub-millimeter resolution in glacier ice (Reinhardt et al., 2001, Della Lunga et al., 2014, Sneed et al., 2015). We will present first results of both approaches with regard to the evaluation of the potential of trace elements as environmental

  10. Development of a scanning nearfield optical microscope for low-temperature investigations of semiconductor nanostructures

    International Nuclear Information System (INIS)

    Hodeck, Kai Friedrich

    2009-01-01

    In the present work the electronic structure of MOCVD-grown InGaAs/GaAs and InAs/GaAs quantum dots which are characterized by a particularly low ground state transition energy, was investigated using Scanning Nearfield Optical Microscopy (SNOM). The pivotal question of the presented investigations is, which influence the interaction of the confined carriers has on the energy states of the biexcitons and the multiexcitons in a quantum dot. Therefore, photoluminescence spectra of single quantum dots were investigated under varying excitation intensity at different temperatures between 5 K and 300 K. The construction of a novel scanning nearfield microscope especially for low temperatures allowed the investigation of single quantum dots. Due to significant improvements of the positioning technology and the shear-force distance control between the sample and the nearfield probe a stable scanning of the quantum dot samples at 5 K could be demonstrated, showing a lateral optical resolution of 200 nm. This way, in the photoluminescence spectroscopy of single quantum dots the thermal linewidth broadening of the detected light was reduced down to a value of less than 1 meV, which allowed the identification of the transitions of biexcitons and multiexcitons. On the basis of the performed measurements, for the InGaAs/GaAs quantum dots a biexciton state was identified, with variable binding energies of 2-7 meV. Furthermore, a positively charged trion state with a binding energy of 11 meV was observed, showing high emission intensity, which can be assigned to the sample doping. Accordingly, for the positively charged biexciton state a binding energy of 11 meV can be announced. For the investigated InAs/GaAs quantum dots a biexciton state with binding energies of 3-4 meV was found. Some of the investigated InAs/GaAs quantum dots showed the formation of positively charged states, in particular of a trion state with a binding energy of 3 meV, and of the positively charged

  11. Development of a scanning nearfield optical microscope for low-temperature investigations of semiconductor nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Hodeck, Kai Friedrich

    2009-02-19

    In the present work the electronic structure of MOCVD-grown InGaAs/GaAs and InAs/GaAs quantum dots which are characterized by a particularly low ground state transition energy, was investigated using Scanning Nearfield Optical Microscopy (SNOM). The pivotal question of the presented investigations is, which influence the interaction of the confined carriers has on the energy states of the biexcitons and the multiexcitons in a quantum dot. Therefore, photoluminescence spectra of single quantum dots were investigated under varying excitation intensity at different temperatures between 5 K and 300 K. The construction of a novel scanning nearfield microscope especially for low temperatures allowed the investigation of single quantum dots. Due to significant improvements of the positioning technology and the shear-force distance control between the sample and the nearfield probe a stable scanning of the quantum dot samples at 5 K could be demonstrated, showing a lateral optical resolution of 200 nm. This way, in the photoluminescence spectroscopy of single quantum dots the thermal linewidth broadening of the detected light was reduced down to a value of less than 1 meV, which allowed the identification of the transitions of biexcitons and multiexcitons. On the basis of the performed measurements, for the InGaAs/GaAs quantum dots a biexciton state was identified, with variable binding energies of 2-7 meV. Furthermore, a positively charged trion state with a binding energy of 11 meV was observed, showing high emission intensity, which can be assigned to the sample doping. Accordingly, for the positively charged biexciton state a binding energy of 11 meV can be announced. For the investigated InAs/GaAs quantum dots a biexciton state with binding energies of 3-4 meV was found. Some of the investigated InAs/GaAs quantum dots showed the formation of positively charged states, in particular of a trion state with a binding energy of 3 meV, and of the positively charged

  12. Atom probe field ion microscopy and related topics: A bibliography 1991

    Energy Technology Data Exchange (ETDEWEB)

    Russell, K.F.; Miller, M.K.

    1993-01-01

    This report contains a bibliography for 1991 on the following topics: Atom probe field ion microscopy; field desorption mass spectrometry; field emission; field ion microscopy; and field emission theory.

  13. Atom probe field ion microscopy and related topics: A bibliography 1991

    International Nuclear Information System (INIS)

    Russell, K.F.; Miller, M.K.

    1993-01-01

    This report contains a bibliography for 1991 on the following topics: Atom probe field ion microscopy; field desorption mass spectrometry; field emission; field ion microscopy; and field emission theory

  14. A cryogenic scanning laser microscope for investigation of dynamical states in long Josephson junctions

    DEFF Research Database (Denmark)

    Holm, Jesper; Mygind, Jesper

    1995-01-01

    The first local oscillators based on moving magnetic flux quanta in long Josephson junctions are being developed for superconducting integrated quasi-optical SIS receivers. In order to further refine these oscillators one has to understand the complex dynamics of these devices. Since the local...... on measurements on different oscillator samples, performed with a novel Cryogenic Scanning Laser Microscope (CSLM) having a spatial resolution of less than ±2.5 μm over a 500 μm×50 μm wide scanning area in the temperature range 2 K-300 K. Even though the dynamical states are extremely sensitive to external noise...... this microscope enables us to make stable in-situ measurements on operating Josephson junctions. Recent results are presented and discussed....

  15. A combined optical and atomic force microscope for live cell investigations

    International Nuclear Information System (INIS)

    Madl, Josef; Rhode, Sebastian; Stangl, Herbert; Stockinger, Hannes; Hinterdorfer, Peter; Schuetz, Gerhard J.; Kada, Gerald

    2006-01-01

    We present an easy-to-use combination of an atomic force microscope (AFM) and an epi-fluorescence microscope, which allows live cell imaging under physiological conditions. High-resolution AFM images were acquired while simultaneously monitoring either the fluorescence image of labeled membrane components, or a high-contrast optical image (DIC, differential interference contrast). By applying two complementary techniques at the same time, additional information and correlations between structure and function of living organisms were obtained. The synergy effects between fluorescence imaging and AFM were further demonstrated by probing fluorescence-labeled receptor clusters in the cell membrane via force spectroscopy using antibody-functionalized tips. The binding probability on receptor-containing areas identified with fluorescence microscopy ('receptor-positive sites') was significantly higher than that on sites lacking receptors

  16. Investigation on the traceability of three dimensional scanning electron microscope measurements based on the stereo-pair technique

    DEFF Research Database (Denmark)

    Bariani, Paolo; De Chiffre, Leonardo; Hansen, Hans Nørgaard

    2005-01-01

    -dimensional topography of the type C roughness standards showed good agreement with the nominal profile wavelength values. An investigation was carried out concerning the traceability of dimensional measurements performed with the scanning electron microscope (SEM) using reconstruction of surface topography through......An investigation was carried out concerning the traceability of dimensional measurements performed with the scanning electron microscope (SEM) using reconstruction of surface topography through stereo-photogrammetry. A theoretical description of the effects that the main instrumental variables...... in the vertical plane using two ISO 5436 type C roughness standards. Results from magnification calibration and tilt angle measurement were used for calculating the theoretical uncertainty on the vertical elevation. Experimental deviations measured on gauge-block steps showed slightly bigger values than those...

  17. In-situ Investigation of Lead-free Solder Alloy Formation Using a Hot-plate Microscope

    DEFF Research Database (Denmark)

    Bergmann, René; Tang, Peter Torben; Hansen, Hans Nørgaard

    2007-01-01

    This work presents the advantages of using a hot-plate microscope for investigation of new (high-temperature) lead- free solders as in-situ analysis tool and preparation equipment. A description of the equipment and the preparation method is given and some examples are outlined. The formation...... phases of the Au-Sn system. The measured values are comparable to those found in the literature. An outlook to further research is also given....

  18. Electromagnetic instabilities attributed to a cross-field ion drift

    Science.gov (United States)

    Chang, C. L.; Wong, H. K.; Wu, C. S.

    1990-01-01

    Instabilities due to a cross-field ion flow are reexamined by including the electromagnetic response of the ions, which has been ignored in existing discussions. It is found that this effect can lead to significant enhancement of the growth rate. Among the new results, a purely growing, electromagnetic unstable mode with a wave vector k parallel to the ambient magnetic field is found. The plasma configuration under consideration is similar to that used in the discussion of the well-known modified-two-stream instability. This instability has a growth rate faster than the ion cyclotron frequency, and is not susceptible to high-plasma-beta stabilization.

  19. [Thirty years of the electron microscope investigation in zoology and parasitology in the Zoological Institute of the Russian Academy of Sciences].

    Science.gov (United States)

    Shatrov, A B

    2003-01-01

    The history of the electron microscope investigations in zoology and parasitology in the Zoological Institute of the Russian Academy of Sciences and progress in scanning and transmission electron microscope investigations in this field of biology to the moment are briefly accounted.

  20. Polarized light and scanning electron microscopic investigation of enamel hypoplasia in primary teeth.

    Science.gov (United States)

    Sabel, Nina; Klingberg, Gunilla; Dietz, Wolfram; Nietzsche, Sandor; Norén, Jörgen G

    2010-01-01

    Enamel hypoplasia is a developmental disturbance during enamel formation, defined as a macroscopic defect in the enamel, with a reduction of the enamel thickness with rounded, smooth borders. Information on the microstructural level is still limited, therefore further studies are of importance to better understand the mechanisms behind enamel hypoplasia. To study enamel hypoplasia in primary teeth by means of polarized light microscopy and scanning electron microscopy. Nineteen primary teeth with enamel hypoplasia were examined in a polarized light microscope and in a scanning electron microscope. The cervical and incisal borders of the enamel hypoplasia had a rounded appearance, as the prisms in the rounded cervical area of the hypoplasia were bent. The rounded borders had a normal surface structure whereas the base of the defects appeared rough and porous. Morphological findings in this study indicate that the aetiological factor has a short duration and affects only certain ameloblasts. The bottom of the enamel hypoplasia is porous and constitutes possible pathways for bacteria into the dentin.

  1. Investigations and characterization of the microstructure of special ceramic materials using the high-resolution electron microscope

    International Nuclear Information System (INIS)

    Kirn, M.

    1979-01-01

    The possibilities to characterize phases and microstructures by direct lattice imaging are indicated in the following work. Ceramic materials are particularly suitable for this as these exhibit a high mechanical stability in the investigation in the transmission electron microscope. First of all the fundamentals of the high-resolution electron microscopy are introduced and the various resulting possibilities to characterize microstructures are presented. A report then follows on experimental observations on undisturbed crystals of special ceramics on a Si 3 N 4 basis. Furthermore, it is shown that the high-resolution electron microscope provides valuable contributions to the determination of structure, in particular of twin variants. Finally, revealing information on the structure of the interfaces was obtained with the help of high-resolution electron microscopy. (orig./IHOE) [de

  2. In-situ investigation of laser surface modifications of WC-Co hard metals inside a scanning electron microscope

    Science.gov (United States)

    Mueller, H.; Wetzig, K.; Schultrich, B.; Pompe, Wolfgang; Chapliev, N. I.; Konov, Vitaly I.; Pimenov, S. M.; Prokhorov, Alexander M.

    1989-05-01

    The investigation of laser interaction with solid surfaces and of the resulting mechanism of surface modification are of technical interest to optimize technological processes, and they are also of fundamental scientific importance. Most instructive indormation is available with the ail of the in-situ techniques. For instance, measuring of the photon emission of the irradiated surface ane the plasma torch (if it is produced) simultaneously to laser action, makes it possible to gain a global characterization of the laser-solid interaction. In order to obtain additional information about surface and structure modifications in microscopic detail , a laser and scanning electron microscope were combined in to a tandem equipment (LASEM). Inside this eqiipment the microscopic observation is carried out directly at the laser irradiated area without any displacement of the sample. In this way, the stepwise development of surface modification during multipulse irradiation is visible in microscopic details and much more reliable information about the surface modification process is obtainable in comparison to an external laser irradiation. Such kind of equipments were realized simultaneously and independently in the Institut of General Physics (Moscow) and the Central Institute of Solid State Physics and Material Research (Dresden) using a CO2 and a LTd-glass-laser, respectively. In the following the advantages and possibilities of a LASEM shall be demonstrated by some selected investigations of WC-CO hardmeta. The results were obtained in collaboration by both groups with the aid of the pulsed CO2-laser. The TEA CO2 laser was transmitted through a ZnSe-window into the sample chamber of the SEM and focused ofAo tfte sample surface. It was operated in TEM - oo mode with a repetition rate of about 1 pulse per second. A peak power density of about 160 MW/cm2 was achieved in front of the sample surface.

  3. Investigation of penetration force of living cell using an atomic force microscope

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Eun Young; Kim, Young Tae; Kim, Dae Eun [Yonsei University, Seoul (Korea, Republic of)

    2009-07-15

    Recently, the manipulation of a single cell has been receiving much attention in transgenesis, in-vitro fertilization, individual cell based diagnosis, and pharmaceutical applications. As these techniques require precise injection and manipulation of cells, issues related to penetration force arise. In this work the penetration force of living cell was studied using an atomic force microscope (AFM). L929, HeLa, 4T1, and TA3 HA II cells were used for the experiments. The results showed that the penetration force was in the range of 2{approx}22 nN. It was also found that location of cell penetration and stiffness of the AFM cantilever affected the penetration force significantly. Furthermore, double penetration events could be detected, due to the multi-membrane layers of the cell. The findings of this work are expected to aid in the development of precision micro-medical instruments for cell manipulation and treatment

  4. Gut hormones in Salamandra salamandra. An immunocytochemical and electron microscopic investigation.

    Science.gov (United States)

    Buchan, A M; Polak, J M; Pearse, A G

    1980-01-01

    Histological, cytochemical and immunocytochemical methods were used in light and electron microscopical studies to demonstrate the presence of a neuroendocrine system in the gut of the urodele, Salamandra salamandra. Cytochemical stains capable of detecting peptide-producing endocrine cells demonstrate cells reacting with Masson's silver (argentaffin) method, Grimelius' argyrophil silver method, masked metachromasia method and the lead haematoxylin stain. Using antisera raised to a variety of mammalian gut peptides, cells containing bombesin-, gastrin-, somatostatin-, substance P- and glucagon-like immunoreactivity were indentified; vasoactive intestinal polypeptide- and substance P-like immunoreactivities were found in nerve fibres in the submucous and myenteric plexus. No immunoreactivity was detected from motilin, gastric inhibitory polypeptide, cholecystokinin or secretin. The ultrastructure of the immunoreactive cells and nerves was revealed by the semithin/thin method. All the cells indentified contained numerous electrondense secretory granules, which varied in their characteristic morphological structure from one cell type to another. The evidence collected in this study indicates that a complex neuroendocrine system regulating gut function is present in this amphibian and may have developed prior to the emergence of the phylum.

  5. The microscopic investigation of structures of moving flux lines by neutron and muon techniques

    International Nuclear Information System (INIS)

    Forgan, E.M.; Charalambous, D.; Kealey, P.G.

    2002-01-01

    We have used a variety of microscopic techniques to reveal the structure and motion of flux line arrangements, when the flux lines in low T c type II superconductors are caused to move by a transport current. Using small-angle neutron scattering by the flux line lattice (FLL), we are able to demonstrate directly the alignment by motion of the nearest-neighbor FLL direction. This tends to be parallel to the direction of flux line motion, as had been suspected from two-dimensional simulations. We also see the destruction of the ordered FLL by plastic flow and the bending of flux lines. Another technique that our collaboration has employed is the direct measurement of flux line motion, using the ultra-high-resolution spectroscopy of the neutron spin-echo technique to observe the energy change of neutrons diffracted by moving flux lines. The muon spin rotation (μSR) technique gives the distribution of values of magnetic field within the FLL. We have recently succeeded in performing μSR measurements while the FLL is moving. Such measurements give complementary information about the local speed and orientation of the FLL motion. We conclude by discussing the possible application of this technique to thin film superconductors. (author)

  6. Microscopical, macroscopical and chemical investigations and their uses in chemotaxonomy of Crataegus pontica C. Koch

    Directory of Open Access Journals (Sweden)

    Nasrollah Ghassemi Dehkordi

    2012-06-01

    Full Text Available The Crataegus genus is widely distributed in Iran. This genus belongs to Rosaceae family and has 17 species in Iran one of which is Crataegus pontica C. Koch. In this paper, we analyzed some microscopic and macroscopic characteristics of this plant, then compared them with other features that were presented previously in previous reports. We analyzed all components in C. pontica, using thin layer chromatography method and then specified the type of flavonoids and hydroxycinnamic acid in C. pontica. Hyproside, rutin and chlorogenic acid were the main flavonoids and hydroxycinnamic occurred acid in this plant. Also, we analyzed its flavonoids quantitatively based on Deutsch Pharmacopoeia method according to hyproside content. Because, to determine the chemosystematic relevancies in some species flavonoids are used, so in this paper we compared C. pontica with 3 other species of its genus such as C. monogyna, C. melanocarpa and C. curvisepala that are found in Iran, and also with the medicinal standard species of Crataegus genus which is called C. oxyacantha. Finally we concluded that hyproside, rutin and chlorogenic acid were the main and common structural components in all species of that genus which were mentioned above.

  7. Neutron diffraction and electron microscopic investigation of decomposition and radiation-induced ageing of Cr-Ni-Ti austenitic alloys

    International Nuclear Information System (INIS)

    Alyab'yev, V.M.; Vologin, V.G.; Dubinin, S.F.; Lapin, S.S.; Parkhomenko, V.D.; Sagaradze, V.V.

    1990-01-01

    The kinetic and structural features of intermetallic ageing of Cr-Ni-Ti austenitic steels are investigated over a wide time interval with neutron diffraction and electron microscopic methods. The size and volume fraction of γ'-particles at the initial (0.25 hr) and later (up to 1000 hr) stages of ageing are determined. From superlattice reflections in neutron diffraction a γ'-phase is identified after irradiation by fast neutrons of stainless steel Kh16N15M3T1, which possesses a high resistance to radiation swelling. (author)

  8. Neonatal lines in the enamel of primary teeth--a morphological and scanning electron microscopic investigation.

    Science.gov (United States)

    Sabel, Nina; Johansson, Carina; Kühnisch, Jan; Robertson, Agneta; Steiniger, Frank; Norén, Jörgen G; Klingberg, Gunilla; Nietzsche, Sandor

    2008-10-01

    The neonatal line (NNL) is in principle found in all primary teeth and the line represents the time of birth. Earlier findings of the appearance of the NNL in light microscope and in microradiographs have shown not only changes in the prism direction of the enamel, but that the NNL has a hypomineralized character. The neonatal line was analyzed in un-decalcified sections of primary lower and central incisors, collected from individuals of different ages utilizing polarized light microscopy, microradiography, scanning electron microscopy (SEM) and X-ray analysis (XRMA). In polarized light the NNL appeared to have a more porous structure than the enamel in general. The appearance of the NNL as a dark line in microradiographs is interpreted as the NNL being less mineralized than neighbouring enamel. Analysis with ImageJ visualized the reduction of the amount of grey value, indicating that the NNL is less mineralized. Analysis of the NNL in SEM showed a reduction of the diameter of enamel prisms, the more narrow diameters continued through the postnatal enamel. A change of the growth direction of the prisms was also observed at the NNL. In a three-dimensional image the NNL appeared as a grove, however, in non-etched enamel no grove was seen. The elemental analyses with XRMA showed no marked changes in the content of C, Ca, P, N, O or S in the area around the NNL. The NNL is an optical phenomenon due to alterations in height, and degree of mineralization of the enamel prisms.

  9. Muscle pathology in myotonic dystrophy: light and electron microscopic investigation in eighteen patients.

    Science.gov (United States)

    Nadaj-Pakleza, A; Lusakowska, A; Sułek-Piątkowska, A; Krysa, W; Rajkiewicz, M; Kwieciński, H; Kamińska, A

    2011-05-01

    Myotonic dystrophy (DM) is the most common muscular dystrophy in adults. Two known genetic subtypes include DM1 (myotonic dystrophy type 1) and DM2 (myotonic dystrophy type 2). Genetic testing is considered as the only reliable diagnostic criterion in myotonic dystrophies. Relatively little is known about DM1 and DM2 myopathology. Thus, the aim of our study was to characterise light and electron microscopic features of DM1 and DM2 in patients with genetically proven types of the disease. We studied 3 DM1 cases and 15 DM2 cases from which muscle biopsies were taken for diagnostic purposes during the period from 1973 to 2006, before genetic testing became available at our hospital. The DM1 group included 3 males (age at biopsy 15-19). The DM2 group included 15 patients (5 men and 10 women, age at biopsy 26-60). The preferential type 1 fibre atrophy was seen in all three DM1 cases in light microscopy, and substantial central nucleation was present in two biopsies. Electron microscopy revealed central nuclei in all three examined muscle biopsies. No other structural or degenerative changes were detected, probably due to the young age of our patients. Central nucleation, prevalence of type 2 muscle fibres, and the presence of pyknotic nuclear clumps were observed in DM2 patients in light microscopy. Among the ultrastructural abnormalities observed in our DM2 group, the presence of internal nuclei, severely atrophied muscle fibres, and lipofuscin accumulation were consistent findings. In addition, a variety of ultrastructural abnormalities were identified by us in DM2. It appears that no single ultrastructural abnormality is characteristic for the DM2 muscle pathology. It seems, however, that certain constellations of morphological changes might be indicative of certain types of myotonic dystrophy.

  10. Reaction kinetics of solid-state cyclization of enalapril maleate investigated by isothermal FT-IR microscopic system.

    Science.gov (United States)

    Wang, S L; Lin, S Y; Chen, T F

    2001-04-01

    To investigate the reaction kinetics of the solid-state degradation process of enalapril maleate, a Fourier transform infrared microspectroscope equipped with thermal analyzer (thermal FT-IR microscopic system) was used. The isothermal stability study was conducted at 120-130 degrees C for 1-2 h and changes in the three-dimensional plots of the IR spectra of enalapril maleate with respect to heating time were observed. The study indicates that the bands at 1649, 1728, and 1751 cm(-1) assigned to intact enalapril maleate gradually reduced in peak intensity with heating time. However, the peak intensities at 1672 and 1738 cm(-1) (due to enalapril diketopiperazine (DKP) formation) and at 3250 cm(-1) (corresponding to water formation) gradually increased with heating time. The solid-state diketopiperazine formation and the degradation process of enalapril maleate via intramolecular cyclization were found to be simultaneous. The isothermal decomposition curves were sigmoidal and were characterized by induction and acceleration periods, indicating the presence of autocatalytic solid-state decompositions. Moreover, the power-law equation (n = 1/4) was found to provide the best fit to the kinetics of decomposition. This isothermal FT-IR microscopic system was easily used to investigate the degradation of enalapril maleate and the concomitant formation of DKP. The solid-state reaction of enalapril maleate required an activation energy of 195+/-12 kJ/mol to undergo the processes of decomposition and intramolecular cyclization.

  11. Microscopic investigation of structural evolution in even-even N = 60 isotones

    International Nuclear Information System (INIS)

    Oudih, M. R.; Fellah, M.; Allal, N. H.; Benhamouda, N.

    2012-01-01

    The ground state properties of even-even N=60 isotones from the neutron-rich to the proton-rich side are investigated within the self-consistent Skyrme-Hartree-Fock-Bogoliubov theory in the triaxial landscape. Quantities such as binding energies and root-mean-square radii are investigated and compared with available experimental data. The evolution of the potential energy surfaces in the (β,γ) deformation plane is presented and discussed.

  12. Theoretical investigation on the magnetic and electric properties in TbSb compound through an anisotropic microscopic model

    Energy Technology Data Exchange (ETDEWEB)

    Ranke, P. J. von, E-mail: von.ranke@uol.com.br; Ribeiro, P. O.; Alho, B. P.; Alvarenga, T. S. T.; Nobrega, E. P.; Caldas, A.; Sousa, V. S. R.; Lopes, P. H. O.; Oliveira, N. A. de [Instituto de Física, Universidade do Estado do Rio de Janeiro–UERJ, Rua São Francisco Xavier, 524, 20550-013 Rio de Janeiro (RJ) (Brazil); Carvalho, A. Magnus G. [Laboratório Nacional de Luz Síncrotron, CNPEM, 13083-970 Campinas, São Paulo (Brazil)

    2016-05-14

    We report the strong correlations between the magnetoresistivity and the magnetic entropy change in the cubic antiferromagnetic TbSb compound. The theoretical investigation was performed through a microscopic model which takes into account the crystalline electrical field anisotropy, exchange coupling interactions between the up and down magnetic sublattices, and the Zeeman interaction. The easy magnetization directions changes from 〈001〉 to 〈110〉 and then to 〈111〉 observed experimentally was successfully theoretically described. Also, the calculation of the temperature dependence of electric resistivity showed good agreement with the experimental data. Theoretical predictions were calculated for the temperature dependence of the magnetic entropy and resistivity changes upon magnetic field variation. Besides, the difference in the spin up and down sublattices resistivity was investigated.

  13. Microscopical investigation of steamside oxide on X20CrMoV121 superheater tubes

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Hansson, Anette Nørgaard; Jensen, Søren A.

    2011-01-01

    X20CrMoV121 is a 12%Cr martensitic steel which has been used in power plants in Europe for many decades. Superheater tubes exposed for various durations up to 135,000 hours in power plants in Denmark at steam temperatures varying from 450 to 575°C were investigated. Light optical and scanning ele...... electron microscopy was used to investigate steamside oxide morphologies. At all temperatures there is a double layered oxide, however, the inner:outer oxide thickness is not always equal. At the lower steam temperature range of...

  14. Investigation of C3S hydration mechanism by transmission electron microscope (TEM) with integrated Super-XTMEDS system.

    Science.gov (United States)

    Sakalli, Y; Trettin, R

    2017-07-01

    Tricalciumsilicate (C 3 S, Alite) is the major component of the Portland cement clinker. Hydration of Alite is decisive in influencing the properties of the resulting material. This is due to its high content in cement. The mechanism of the hydration of C 3 S is very complicated and not yet fully understood. There are different models describing the hydration of C 3 S in various ways. In this work for a better understanding of hydration mechanism, the hydrated C 3 S was investigated by using the transmission electron microscope (TEM) and for the first time, the samples for the investigations were prepared by using of focused ion beam from sintered pellets of C 3 S. Also, an FEI Talos F200x with an integrated Super-X EDS system was used for the investigations. FEI Talos F200X combines outstanding high-resolution S/TEM and TEM imaging with energy dispersive X-ray spectroscopy signal detection, and 3D chemical characterization with compositional mapping. TEM is a very powerful tool for material science. A high energy beam of electrons passes through a very thin sample, and the interactions between the electrons and the atoms can be used to observe the structure of the material and other features in the structure. TEM can be used to study the growth of layers and their composition. TEM produces high-resolution, two-dimensional images and will be used for a wide range of educational, science and industry applications. Chemical analysis can also be performed. The purpose of these investigations was to get the information about the composition of the C-S-H phases and some details of the nanostructure of the C-S-H phases. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

  15. Electron microscopic investigations of tracks of Cf252 fission fragments in quartz glass

    International Nuclear Information System (INIS)

    Werba, T.; Granzer, F.

    1977-01-01

    Using a single stage carbon replication technique, track pits of Cf 252 -fission products in quartz glass could be revealed by transmission electron microscopy with a high degree of resolution. From the shape of the track pits the angles of incidence of the nuclear particles were determined down to extremely small angles. In addition track pits on the fracture surface of irradiated quartz glass samples have been investigated by scanning electron microscopy. (author)

  16. Electron microscope investigations of activated chalcopyrite particles via the FLSmidth® ROL process

    DEFF Research Database (Denmark)

    Karcz, Adam Paul; Damø, Anne Juul; Illerup, Jytte Boll

    2017-01-01

    in surface passivation problems associated with atmospheric leaching, this process is typically able to achieve copper recoveries exceeding 95% in 6 h. An important factor contributing to this extraordinary process performance is a mineral preconditioning step (the focus of this study), which uses between 0.......1 and 5 mol percent of copper (II) to dope the lattice and thereby “activate” chalcopyrite. Since lattice restructuring can have such a dramatic influence on semiconductor reactivity, the associated physico-chemical phenomena are worth studying. In this regard, we investigate the relationship between...... insights into the impact of applying chemical activation as a pretreatment for mechanochemical processes....

  17. Scanning electron microscope investigation of the structural growth in thick sputtered coatings

    Science.gov (United States)

    Spalvins, T.

    1975-01-01

    Sputtered S-Monel, silver, and 304 stainless steel coatings and molybdenum disulfide coatings were deposited on mica and metal substrates with various surface finishes to investigate the structural growth of the coating by scanning electron microscopy. The geometry and the surface morphology of the nodules are characterized. Compositional changes within the coating were analyzed by energy dispersive X-ray analysis. Defects in the surface finish act as preferential nucleation sites and form isolated overlapping and complex nodules and various unusual surface overgrowths on the coating. The nodule boundaries are very vulnerable to chemical etching and these nodules do not disappear after full annealing. Further, they have undesirable effects on mechanical properties; cracks are initiated at the nodules when the coating is stressed by mechanical forces.

  18. Atomic force microscopic investigation of commercial pressure sensitive adhesives for forensic analysis.

    Science.gov (United States)

    Canetta, Elisabetta; Adya, Ashok K

    2011-07-15

    Pressure sensitive adhesive (PSA), such as those used in packaging and adhesive tapes, are very often encountered in forensic investigations. In criminal activities, packaging tapes may be used for sealing packets containing drugs, explosive devices, or questioned documents, while adhesive and electrical tapes are used occasionally in kidnapping cases. In this work, the potential of using atomic force microscopy (AFM) in both imaging and force mapping (FM) modes to derive additional analytical information from PSAs is demonstrated. AFM has been used to illustrate differences in the ultrastructural and nanomechanical properties of three visually distinguishable commercial PSAs to first test the feasibility of using this technique. Subsequently, AFM was used to detect nanoscopic differences between three visually indistinguishable PSAs. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  19. Petrographic microscope investigation of mortar and ceramic technologies for the conservation of the built heritage

    Science.gov (United States)

    Pavia, S.; Caro, S.

    2007-07-01

    Polarised-light (or petrographic) microscopy has been widely applied to heritage materials to assess composition and diagnose damage. However, instead, this paper focuses on the petrographic investigation of brick and mortar technologies for the production of quality repair materials compatible with their adjacent fabrics. Furthermore, the paper relates production technologies to the physical properties of the materials fabricated, and thus their final quality and durability. According to Cesare Brandi´s theory of compatibility (the 20th century architect on whose work modern conservation theory and practice are largely based) existing historic materials should be replaced with their equivalent. This paper demonstrates that polarised-light microscopy provides data on the origin and nature of raw materials, and processing parameters such as blending, mixing, firing, calcination and slaking, and how these relate to the quality of the final product. In addition, this paper highlights the importance of production technologies as these directly impact the physical properties of the materials fabricated and thus determine their final quality and durability. In this context, the paper investigates mortar calcination and slaking, two important operations in the manufacture of building limes that govern the reactivity, shrinkage and water retention of a lime binder which will impact mortar's properties such as workability, plasticity and carbonation speed, and these in turn will determine the ease of execution, durability and strength of a lime mortar. Petrographic analysis also provides evidence of ceramic technology including identification of local or foreign production and processing parameters such as sieving, blending, mixing and firing. A petrographic study of the ceramic matrix coupled to the diagnosis of mineral phases formed during firing allows to quantify sintering and vitrification and thus determine firing temperatures. Finally, certain features of the raw

  20. Investigation into macroscopic and microscopic behaviors of wet granular soils using discrete element method and X-ray computed tomography

    Science.gov (United States)

    Than, Vinh-Du; Tang, Anh-Minh; Roux, Jean-Noël; Pereira, Jean-Michel; Aimedieu, Patrick; Bornert, Michel

    2017-06-01

    We present an investigation into macroscopic and microscopic behaviors of wet granular soils using the discrete element method (DEM) and the X-ray Computed Tomography (XRCT) observations. The specimens are first prepared in very loose states, with frictional spherical grains in the presence of a small amount of an interstitial liquid. Experimental oedometric tests are carried out with small glass beads, while DEM simulations implement a model of spherical grains joined by menisci. Both in experiments and in simulations, loose configurations with solid fraction as low as 0.30 are prepared under low stress, and undergo a gradual collapse in compression, until the solid fraction of cohesionless bead packs (0.58 to 0.6) is obtained. In the XRCT tests, four 3D tomography images corresponding to different typical stages of the compression curve are used to characterize the microstructure.

  1. A Photoemission Electron Microscope Investigation of Chemical Vapor Deposition Diamond Films and Diamond Nucleation

    Science.gov (United States)

    Wang, Congjun

    1993-01-01

    CVD diamond nucleation is investigated using the hot filament technique. The stability of CVD diamond at elevated temperatures in vacuum, O_2, and atomic hydrogen environments are studied using photoemission electron microscopy (PEEM) combined with in-vacuo x-ray photoelectron spectroscopy (XPS). Dissolution, oxidation, and atomic hydrogen etching processes of CVD diamond are observed in real-time. Low field cold electron emission from CVD diamond films has been observed for the first time by PEEM. Nucleation density Mo substrates could be increased from 10^4 to rm 10 ^8/cm^2 by polishing. Heating the substrate to 870^circC in vacuum prior to deposition, or above 1000^ circC at the beginning of deposition, reduced nucleation by more than 100-fold. Reduction in nucleation sites is attributed to annealing. Nucleation on Mo _2C substrates was found to be very poor rm (10^4/cm^2), which shows carbide alone does not promote nucleation. Carbide formation may remove nucleation sites. CVD diamond was found to dissolve into the Mo substrate in vacuum at about 1200^circ C. XPS showed formation of Mo_2 C when the diamond dissolved. Diamond oxidation to gas phase products occurred directly at about 600 ^circC, with no observable participation by the substrate. No detectable etching by atomic hydrogen at a pressure of 1times10^{-4 } torr was observed. Boron doped and "pure" CVD diamond films were found to emit electrons at room temperature under the action of the accelerating electric field of the PEEM (about 30 kV/cm) without photon excitation. The mechanism underlying this phenomenon was investigated with PEEM and by studying the emission current-vs-voltage characteristics of the CVD diamond films. Morphology and crystalline orientation were found to play only a minor role. Impurities in the CVD diamond structure lowers the potential barrier substantially; tunneling of electrons into the vacuum is facile. The effective work function of the emitting CVD diamond films is

  2. Atom probe field ion microscopy and related topics: A bibliography 1992

    Energy Technology Data Exchange (ETDEWEB)

    Russell, K.F.; Godfrey, R.D.; Miller, M.K.

    1993-12-01

    This bibliography contains citations of books, conference proceedings, journals, and patents published in 1992 on the following types of microscopy: atom probe field ion microscopy (108 items); field emission microscopy (101 items); and field ion microscopy (48 items). An addendum of 34 items missed in previous bibliographies is included.

  3. Electron microscopic investigations of the as-synthesised and dissociated Y:124 HTSC phases

    International Nuclear Information System (INIS)

    Srivastava, A.K.; Ramakrishna, K.; Srivastava, O.N.

    1992-01-01

    The Y:124 was synthesised at ambient oxygen pressure using an oxygen enhancer (NaNO 3 ). The as-synthesised material was thermally dissociated at 915degC for various time spans, e.g., 1, 2 and 5 min. X-ray diffraction (XRD) results showed that the undissociated sample corresponds to the Y:124 phase, whereas the dissociated samples consisted of mixed phases. For the samples dissociated for 1 min these were Y:124 and Y:123 (with some traces of CuO), for dissociation times of 2 and 5 min these were dominantly Y:123 and CuO. From R-T and L-T (inductance-temperature) measurements, it was found that the undissociated Y:124 possesses a Tc(R=0)∝80 K and there is no drop in inductance for dissociated samples (2 and 5 min). Microstructural investigations of Y:124 revealed that the material dissociated for 1 min is biphasic, consisting of Y:124 and Y:123. Besides stacking disorder, local area superstructures along ''c'' emanating from the native Y:124 phase were also observed. This is thought to ensue from the random and sequential removal of Cu-O chains from the Y:124 structure. The sample subjected to longer dissociation times, i.e., 2 and 5 min consists of Y:123 and CuO precipitates. For longer dissociation times, e.g., 2 min and above, the Y:124 phase nearly completely converts into Y:123 and CuO. (orig.)

  4. Analytical high resolution microscopic investigation of organic coating on co-composted biochar

    Science.gov (United States)

    Albu, Mihaela; Mayrhofer, Claudia; Hagemann, Nikolas; Joseph, Stephen; Hofer, Ferdinand; Kothleitner, Gerald

    2017-04-01

    Aged and/or co-composted biochar amendment improves soil fertility by changing certain proprieties like the porosity and sorption capacity, the redox properties, water holding capacity and nutrient transformations in soil. The beneficial properties have been correlated with surface functional groups resulting from the interactions between black carbon particles, inorganic and organic matter in the soil and soil biota, manure or other compost feedstock. As a result, porous organic layer and organo-mineral phases on the biochar surfaces are formed. This paper presents a detailed analysis of the porous layer and organo-mineral phases formed on co-composted biochar by using high resolution scanning transmission electron microscopy (STEM) and electron energy loss (EELS) as well as energy dispersive X-ray spectroscopy (EDX). The fine structure fingerprints of carbon and nitrogen edges have been used to identify the functional groups, while EDX was used to identify the mineral phases. However, in order to achieve undoubtable results a novel preparation technic of the sample has been developed. The preparation involved 3D gold sputtering on the black carbon particles in order to preserve the surface intact, embedding in resin and, ultrathin microtome cutting. The investigation was carried out using a probe corrected Titan 3G, at a voltage of 60 kV and in cryo-condition, with an EELS energy resolution of 0.15 eV and a spatial resolution down to atomic layers. We proved the presence of both C and N functional groups in the porous, heterogeneous and hydrophilic organic layer and organo-mineral agglomerates. The organic layer fully covered the outer surface of the black carbon piece, but also the surface of internal pores. Its thickness varied from 500-1000 nm on the outer surface down to a couple of nanometres on internal pores. The observed C functional groups have been identified to correspond to: aromatic, aromatic with side chain, ketone, aliphatic, carboxyl/amine carbon

  5. Atomic force and optical near-field microscopic investigations of polarization holographic gratings in a liquid crystalline azobenzene side-chain polyester

    DEFF Research Database (Denmark)

    Ramanujam, P.S.; Holme, N.C.R.; Hvilsted, S.

    1996-01-01

    Atomic force and scanning near-field optical microscopic investigations have been carried out on a polarization holographic grating recorded in an azobenzene side-chain Liquid crystalline polyester. It has been found that immediately following laser irradiation, a topographic surface grating......-field optical microscopic scanning of the grating reveals, however, that the bulk of the film remains optically anisotropic. (C) 1996 American Institute of Physics....

  6. Gap controlled plasmon-dielectric coupling effects investigated with single nanoparticle-terminated atomic force microscope probes.

    Science.gov (United States)

    Huang, Qian; Teran Arce, Fernando; Lee, Joon; Yoon, Ilsun; Villanueva, Joshua; Lal, Ratnesh; Sirbuly, Donald J

    2016-10-06

    Precise positioning of a plasmonic nanoparticle (NP) near a small dielectric surface is not only necessary for understanding gap-dependent interactions between a metal and dielectric but it is also a critical component in building ultrasensitive molecular rulers and force sensing devices. In this study we investigate the gap-dependent scattering of gold and silver NPs by controllably depositing them on an atomic force microscope (AFM) tip and monitoring their scattering within the evanescent field of a tin dioxide nanofiber waveguide. The enhanced distance-dependent scattering profiles due to plasmon-dielectric coupling effects show similar decays for both gold and silver NPs given the strong dependence of the coupling on the decaying power in the near-field. Experiments and simulations also demonstrate that the NPs attached to the AFM tips act as free NPs, eliminating optical interference typically observed from secondary dielectric substrates. With the ability to reproducibly place individual plasmonic NPs on an AFM tip, and optically monitor near-field plasmon-dielectric coupling effects, this approach allows a wide-variety of light-matter interactions studies to be carried out on other low-dimensional nanomaterials.

  7. An investigation of the space distribution of Ulva microscopic propagules and ship-based experiment of mitigation using modified clay.

    Science.gov (United States)

    Li, Jing; Song, Xiuxian; Zhang, Yue; Pan, Jun; Yu, Zhiming

    2017-04-15

    Previous studies suggested that the removal of Ulva microscopic propagules (UMP) from cradle water might restrict the formation and expansion of green tides in the Yellow Sea, China. In this study, the distribution characteristics of UMP in the southern Yellow Sea was investigated, and then a flocculation experiment of UMP using modified clay (MC) was conducted at a selected station of the research cruise. The results indicated that the distribution of green algae thalli is one of the main factors that directly influence UMP distribution. UMP density was strongly negatively correlated with the distance between the sampling station and the centre of the area containing floating Ulva (r=-0.618***, n=83). >80% of the UMP was removed from the water column after MC application at a concentration of 0.1g/L, and MC applied at a concentration of 0.5g/L reduced the germination rate to 0.3%. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Xenon gas field ion source from a single-atom tip

    Science.gov (United States)

    Lai, Wei-Chiao; Lin, Chun-Yueh; Chang, Wei-Tse; Li, Po-Chang; Fu, Tsu-Yi; Chang, Chia-Seng; Tsong, T. T.; Hwang, Ing-Shouh

    2017-06-01

    Focused ion beam (FIB) systems have become powerful diagnostic and modification tools for nanoscience and nanotechnology. Gas field ion sources (GFISs) built from atomic-size emitters offer the highest brightness among all ion sources and thus can improve the spatial resolution of FIB systems. Here we show that the Ir/W(111) single-atom tip (SAT) can emit high-brightness Xe+ ion beams with a high current stability. The ion emission current versus extraction voltage was analyzed from 150 K up to 309 K. The optimal emitter temperature for maximum Xe+ ion emission was ˜150 K and the reduced brightness at the Xe gas pressure of 1 × 10-4 torr is two to three orders of magnitude higher than that of a Ga liquid metal ion source, and four to five orders of magnitude higher than that of a Xe inductively coupled plasma ion source. Most surprisingly, the SAT emitter remained stable even when operated at 309 K. Even though the ion current decreased with increasing temperature, the current at room temperature (RT) could still reach over 1 pA when the gas pressure was higher than 1 × 10-3 torr, indicating the feasibility of RT-Xe-GFIS for application to FIB systems. The operation temperature of Xe-SAT-GFIS is considerably higher than the cryogenic temperature required for the helium ion microscope (HIM), which offers great technical advantages because only simple or no cooling schemes can be adopted. Thus, Xe-GFIS-FIB would be easy to implement and may become a powerful tool for nanoscale milling and secondary ion mass spectroscopy.

  9. The first isolation of Cochliopodium gulosum Schaeffer, 1926 (Lobosea, Himatismenida) since its initial description. I. light-microscopical investigation

    OpenAIRE

    Kudryavtsev, Alexander

    1999-01-01

    A marine lobose amoeba possessing characteristic features of the genus Cochliopodium (Hertwig and Lesser, 1874) Kudryavtsev, 1999 was found in the upper layer of sand at the beach of Keret Island, Kandalaksha Bay, the White Sea. Light-microscopical identity of this isolate and Cochliopodium gulosum Schaeffer, 1926 has been shown. This species has never been isolated and studied since its initial description. Its validity and generic position are confirmed by the results of light-microscopical...

  10. Atom probe field ion microscopy and related topics: A bibliography 1989

    Energy Technology Data Exchange (ETDEWEB)

    Miller, M.K.; Hawkins, A.R.; Russell, K.F.

    1990-12-01

    This bibliography includes references related to the following topics: atom probe field ion microscopy (APFIM), field ion spectroscopy (FIM), field emission microscopy (FEM), liquid metal ion sources (LMIS), scanning tunneling microscopy (STM), and theory. Technique-orientated studies and applications are included. This bibliography covers the period 1989. The references contained in this document were compiled from a variety of sources including computer searches and personal lists of publications.

  11. Atom probe field-ion microscopy and related topics: A bibliography, 1988

    Energy Technology Data Exchange (ETDEWEB)

    Miller, M.K.; Hawkins, A.R.

    1989-10-01

    This bibliography includes references related to the following topics: field-ion microscopy (FIM), field emission microscopy (FEM), atom probe field-ion microscopy (APFIM), and liquid metal ion sources (LMIS). Technique-orientated studies and applications are included. The references contained in this document were compiled from a variety of sources including computer searches and personal lists of publications. To reduce the length of this document, the references have been reduced to the minimum necessary to locate the articles.

  12. Microscope basics.

    Science.gov (United States)

    Sluder, Greenfield; Nordberg, Joshua J

    2013-01-01

    This chapter provides information on how microscopes work and discusses some of the microscope issues to be considered in using a video camera on the microscope. There are two types of microscopes in use today for research in cell biology-the older finite tube-length (typically 160mm mechanical tube length) microscopes and the infinity optics microscopes that are now produced. The objective lens forms a magnified, real image of the specimen at a specific distance from the objective known as the intermediate image plane. All objectives are designed to be used with the specimen at a defined distance from the front lens element of the objective (the working distance) so that the image formed is located at a specific location in the microscope. Infinity optics microscopes differ from the finite tube-length microscopes in that the objectives are designed to project the image of the specimen to infinity and do not, on their own, form a real image of the specimen. Three types of objectives are in common use today-plan achromats, plan apochromats, and plan fluorite lenses. The concept of mounting video cameras on the microscope is also presented in the chapter. Copyright © 2003 Elsevier Inc. All rights reserved.

  13. Nuclear microscopic investigations into the elemental changes in the substantia nigra of unilaterally MPTP-lesioned Parkinsonian monkeys

    Science.gov (United States)

    Thong, P. S. P.; He, Y.; Lee, T.; Watt, F.

    1997-07-01

    Various transition metals, particularly iron, have been implicated in the aetiology of the neurodegenerative disease, Parkinson's disease, in which there is a characteristic loss of cells in the substantia nigra (SN) region of the brain. In this study, monkeys were unilaterally lesioned with the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydro-pyridine (MPTP) to obtain primate models of parkinsonism, with the non-lesioned side of the brain serving as controls. The monkeys were sacrificed at one day, one week, two weeks, one month and one year after lesioning to investigate the time dependent elemental changes in the parkinsonian SN. Sections of the brain encompassing both the lesioned and non-lesioned SNs were analysed using the National University of Singapore nuclear microscope. Adjacent sections were tyrosine hydroxylase (TH) immunohistochemically stained to provide complementary information on dopaminergic cell loss and to facilitate definition of the SN boundaries during data analysis. In one-day and one-week monkeys (representing early stages of the disease), there were no changes in elemental concentrations within experimental errors and the adjacent TH-stained sections did not show apparent cell loss in the SN. At two weeks, cell loss was seen in the lesioned SN compared to the control SN. Although there was no bulk increase in SN iron, localised accumulation of iron in granules containing up to 15% by weight iron was observed in the lesioned SN of one of the two-week monkeys. An average 15% increase in nigral iron, significant at the 90% confidence level ( p cell loss in the lesioned SN. In one-year samples (representing the advanced stage of the disease) there was a significant ( p cells in the lesioned SN was apparent from the adjacent TH-stained sections. These preliminary results suggest that while bulk increase in iron may seem to follow cell death, localised accumulation of SN iron in the early stages of the disease may play an important role in

  14. Microwave Microscope

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Makes ultra-high-resolution field measurements. The Microwave Microscope (MWM) has been used in support of several NRL experimental programs involving sea...

  15. Investigations in space-related molecular biology. [cryo-electron microscopic and diffraction studies on terrestrial and extraterrestrial specimens

    Science.gov (United States)

    Fernandez-Moran, H.; Pritzker, A. N.

    1974-01-01

    Improved instrumentation and preparation techniques for high resolution, high voltage cryo-electron microscopic and diffraction studies on terrestrial and extraterrestrial specimens are reported. Computer correlated ultrastructural and biochemical work on hydrated and dried cell membranes and related biological systems provided information on membrane organization, ice crystal formation and ordered water, RNA virus linked to cancer, lunar rock samples, and organometallic superconducting compounds. Apollo 11, 12, 14, and 15 specimens were analyzed

  16. Microscopic investigation of interface in extraction systems rare earth nitrates-HNO3-di(2-ethylhexyl)-phosphoric acid-toluene

    International Nuclear Information System (INIS)

    Kizim, N.F.; Lar'kov, A.P.

    1988-01-01

    Formation process of interfacial film in Ln(NO 3 ) 3 -HNO 3 -HDEMP-C 6 H 5 CH 3 extraction systems is studied on the basis if interface microscopic investigations. It is found, that interfacial film formation is complicated by other phenomena: spontaneous surface convection, emulsification, solid-state particles occurrence in the interfacial layer. External factors effect on film formation process is considered

  17. Atom probe field ion microscopy and related topics: A bibliography 1993

    International Nuclear Information System (INIS)

    Godfrey, R.D.; Miller, M.K.; Russell, K.F.

    1994-10-01

    This bibliography, covering the period 1993, includes references related to the following topics: atom probe field ion microscopy (APFIM), field emission (FE), and field ion microscopy (FIM). Technique-oriented studies and applications are included. The references contained in this document were compiled from a variety of sources including computer searches and personal lists of publications. To reduce the length of this document, the references have been reduced to the minimum necessary to locate the articles. The references are listed alphabetically by authors, an Addendum of references missed in previous bibliographies is included

  18. Atom probe field ion microscopy and related topics: A bibliography 1990

    Energy Technology Data Exchange (ETDEWEB)

    Russell, K.F.; Miller, M.K.

    1991-12-01

    This bibliography includes references related to the following topics: atom probe field ion microscopy (APFIM), field ion microscopy (FIM), field emission (FE), ion sources, and field desorption mass microscopy (FDMM). Technique-orientated studies and applications are included. The bibliography covers the period 1990. The references contained in this document were compiled from a variety of sources including computer searches and personal lists of publications. To reduce the length of this document, the references have been reduced to the minimum necessary to locate the articles. The references, listed alphabetically by authors, are subdivided into the categories listed in paragraph one above. An Addendum of references missed in previous bibliographies is included.

  19. Atom probe field ion microscopy and related topics: A bibliography 1993

    Energy Technology Data Exchange (ETDEWEB)

    Godfrey, R.D.; Miller, M.K.; Russell, K.F.

    1994-10-01

    This bibliography, covering the period 1993, includes references related to the following topics: atom probe field ion microscopy (APFIM), field emission (FE), and field ion microscopy (FIM). Technique-oriented studies and applications are included. The references contained in this document were compiled from a variety of sources including computer searches and personal lists of publications. To reduce the length of this document, the references have been reduced to the minimum necessary to locate the articles. The references are listed alphabetically by authors, an Addendum of references missed in previous bibliographies is included.

  20. Field Ion Microscopy and Atom Probe Tomography of Metamorphic Magnetite Crystals

    Science.gov (United States)

    Kuhlman, K.; Martens, R. L.; Kelly, T. F.; Evans, N. D.; Miller, M. K.

    2001-01-01

    Magnetite has been analysed using Field Ion Microscopy (FIM) and Atom Probe Tomography (APT), highly attractive techniques for the nanoanalysis of geological materials despite the difficulties inherent in analyzing semiconducting and insulating materials. Additional information is contained in the original extended abstract.

  1. MicroRaman, PXRD, EDS and microscopic investigation of magnesium calcite biomineral phases. The case of sea urchin biominerals

    Science.gov (United States)

    Borzęcka-Prokop, B.; Wesełucha-Birczyńska, A.; Koszowska, E.

    2007-02-01

    This study concerns Mg-calcite characterization (and in particular molecular structure and microstructural studies of mineral phases) of a sea urchin mineralised test and spines. Sea urchins are spiny sea animals (kingdom Animalia, phylum Echinodermata, class Echinoidea). Microscopic observations, SEM, EDS, PXRD and spectroscopic microRaman methods have been applied to characterize the biomineral parts of the sea urchin. The latter technique is very useful in research of biological systems and especially suitable for monitoring differences within biomineral phases exhibiting varieties of morphological forms. Crystalline magnesium calcium carbonate, Mg xCa 1- xCO 3 (magnesian calcite; space group R-3 cH; a = 4.9594(8) Å, c = 16.886(6) Å), has been identified as the predominant biomineral component.

  2. [Electron microscopic investigation of CD4+ lymphocyte cell line C8166 after infection with simian immunodeficiency virus (SIV)].

    Science.gov (United States)

    Kaup, F J; Bingger, K; Mätz-Rensing, K; Stahl-Hennig, C; Schneider, T; Hofmann, P

    2003-04-01

    The SIV infection of rhesus macaques (Macaca mulatta) is the most appropriate animal model in HIV research. The permanent human T-cell line C8166 is used for in vitro SIV propagation. This paper describes ultrastructural features of the cells after infection with SIVmac. The C8166 cells are ultrastructurally characterized by a heterogenous morphology which is independent of the infection. SIV induced cell syncytia are observed 18 hours after infection. Viral particles and budding occur 48 hours p.i with a peak at the day 8. Viral particles present the typical lentiviral morphology. Using the monoclonal antibody anti SIVp28 and ultra small (0.8 nm) immunogold-silver enhancement technique, we are able to demonstrate SIV antigen immunoelectron microscopically. Therefore, this ultrastructural method is suitable to detect SIV antigen in in vivo experiments with C8166 cells from day 8 p.i. serving as positive control.

  3. Investigation of acoustic waves generated in an elastic solid by a pulsed ion beam and their application in a FIB based scanning ion acoustic microscope

    Energy Technology Data Exchange (ETDEWEB)

    Akhmadaliev, C.

    2004-12-01

    The aim of this work is to investigate the acoustic wave generation by pulsed and periodically modulated ion beams in different solid materials depending on the beam parameters and to demonstrate the possibility to apply an intensity modulated focused ion beam (FIB) for acoustic emission and for nondestructive investigation of the internal structure of materials on a microscopic scale. The combination of a FIB and an ultrasound microscope in one device can provide the opportunity of nondestructive investigation, production and modification of micro- and nanostructures simultaneously. This work consists of the two main experimental parts. In the first part the process of elastic wave generation during the irradiation of metallic samples by a pulsed beam of energetic ions was investigated in an energy range from 1.5 to 10 MeV and pulse durations of 0.5-5 {mu}s, applying ions with different masses, e.g. oxygen, silicon and gold, in charge states from 1{sup +} to 4{sup +}. The acoustic amplitude dependence on the ion beam parameters like the ion mass and energy, the ion charge state, the beam spot size and the pulse duration were of interest. This work deals with ultrasound transmitted in a solid, i.e. bulk waves, because of their importance for acoustic transmission microscopy and nondestructive inspection of internal structure of a sample. The second part of this work was carried out using the IMSA-100 FIB system operating in an energy range from 30 to 70 keV. The scanning ion acoustic microscope based on this FIB system was developed and tested. (orig.)

  4. Investigation of acoustic waves generated in an elastic solid by a pulsed ion beam and their application in a FIB based scanning ion acoustic microscope

    International Nuclear Information System (INIS)

    Akhmadaliev, C.

    2004-12-01

    The aim of this work is to investigate the acoustic wave generation by pulsed and periodically modulated ion beams in different solid materials depending on the beam parameters and to demonstrate the possibility to apply an intensity modulated focused ion beam (FIB) for acoustic emission and for nondestructive investigation of the internal structure of materials on a microscopic scale. The combination of a FIB and an ultrasound microscope in one device can provide the opportunity of nondestructive investigation, production and modification of micro- and nanostructures simultaneously. This work consists of the two main experimental parts. In the first part the process of elastic wave generation during the irradiation of metallic samples by a pulsed beam of energetic ions was investigated in an energy range from 1.5 to 10 MeV and pulse durations of 0.5-5 μs, applying ions with different masses, e.g. oxygen, silicon and gold, in charge states from 1 + to 4 + . The acoustic amplitude dependence on the ion beam parameters like the ion mass and energy, the ion charge state, the beam spot size and the pulse duration were of interest. This work deals with ultrasound transmitted in a solid, i.e. bulk waves, because of their importance for acoustic transmission microscopy and nondestructive inspection of internal structure of a sample. The second part of this work was carried out using the IMSA-100 FIB system operating in an energy range from 30 to 70 keV. The scanning ion acoustic microscope based on this FIB system was developed and tested. (orig.)

  5. Argon broad ion beam tomography in a cryogenic scanning electron microscope: a novel tool for the investigation of representative microstructures in sedimentary rocks containing pore fluid.

    Science.gov (United States)

    Desbois, G; Urai, J L; Pérez-Willard, F; Radi, Z; Offern, S; Burkart, I; Kukla, P A; Wollenberg, U

    2013-03-01

    The contribution describes the implementation of a broad ion beam (BIB) polisher into a scanning electron microscope (SEM) functioning at cryogenic temperature (cryo). The whole system (BIB-cryo-SEM) provides a first generation of a novel multibeam electron microscope that combines broad ion beam with cryogenic facilities in a conventional SEM to produce large, high-quality cross-sections (up to 2 mm(2)) at cryogenic temperature to be imaged at the state-of-the-art SEM resolution. Cryogenic method allows detecting fluids in their natural environment and preserves samples against desiccation and dehydration, which may damage natural microstructures. The investigation of microstructures in the third dimension is enabled by serial cross-sectioning, providing broad ion beam tomography with slices down to 350 nm thick. The functionalities of the BIB-cryo-SEM are demonstrated by the investigation of rock salts (synthetic coarse-grained sodium chloride synthesized from halite-brine mush cold pressed at 150 MPa and 4.5 GPa, and natural rock salt mylonite from a salt glacier at Qom Kuh, central Iran). In addition, results from BIB-cryo-SEM on a gas shale and Boom Clay are also presented to show that the instrument is suitable for a large range of sedimentary rocks. For the first time, pore and grain fabrics of preserved host and reservoir rocks can be investigated at nm-scale range over a representative elementary area. In comparison with the complementary and overlapping performances of the BIB-SEM method with focused ion beam-SEM and X-ray tomography methods, the BIB cross-sectioning enables detailed insights about morphologies of pores at greater resolution than X-ray tomography and allows the production of large representative surfaces suitable for FIB-SEM investigations of a specific representative site within the BIB cross-section. © 2013 The Authors Journal of Microscopy © 2013 Royal Microscopical Society.

  6. Microscopic colitis

    DEFF Research Database (Denmark)

    Münch, A; Aust, D; Bohr, Jakob

    2012-01-01

    Microscopic colitis (MC) is an inflammatory bowel disease presenting with chronic, non-bloody watery diarrhoea and few or no endoscopic abnormalities. The histological examination reveals mainly two subtypes of MC, lymphocytic or collagenous colitis. Despite the fact that the incidence in MC has...... been rising over the last decades, research has been sparse and our knowledge about MC remains limited. Specialists in the field have initiated the European Microscopic Colitis Group (EMCG) with the primary goal to create awareness on MC. The EMCG is furthermore a forum with the intention to promote...

  7. Martian Microscope

    Science.gov (United States)

    2004-01-01

    The microscopic imager (circular device in center) is in clear view above the surface at Meridiani Planum, Mars, in this approximate true-color image taken by the panoramic camera on the Mars Exploration Rover Opportunity. The image was taken on the 9th sol of the rover's journey. The microscopic imager is located on the rover's instrument deployment device, or arm. The arrow is pointing to the lens of the instrument. Note the dust cover, which flips out to the left of the lens, is open. This approximated color image was created using the camera's violet and infrared filters as blue and red.

  8. High-voltage electron-microscope investigation of point-defect agglomerates in irradiated copper during in-situ annealing

    International Nuclear Information System (INIS)

    Jaeger, W.; Urban, K.; Frank, W.

    1980-01-01

    Thin copper foils were irradiated with 650 keV electrons at 10 K in a high-voltage electron microscope (HVEM) to doses phi in the range 2 x 10 23 electrons/m 2 approximately 25 electrons /m 2 and then annealed in situ up to room temperature and outside the HVEM between room temperature and 470 K. During irradiation visible defect clusters were formed only at phi >= 2.5 x 10 24 electrons/m 2 . At smaller doses defect clusters became visible after annealing at 50 K. Between 50 K and 120 K further clusters, mainly dislocation loops on brace111 planes, appeared. Above 120 K, particularly between 160 K and 300 K, some of the dislocation loops became glissile. They glided out of the specimens or agglomerated to larger clusters of frequently complex shapes. As a consequence between 160 K and 300 K the cluster density decreased strongly, whereas the mean cluster size increased monotonously through the entire range of annealing temperatures covered. Contrast analyses between 180 K and 400 K revealed that the great majority of the dislocation loops were of interstitial type. At 470 K a new type of small clusters emerged, presumably of vacancy type. These observations are compared with other studies on electron-irradiated copper and with the current models of radiation damage in metals. (author)

  9. ELECTRON MICROSCOPIC INVESTIGATION OF YTTRIUM ALUMINUM GARNET POWDERS Y3AL5O12, SYNTHESIZED BY SOL–GEL METHOD

    Directory of Open Access Journals (Sweden)

    A. E. Baranchikov

    2015-09-01

    Full Text Available Subject of Study. The paper presents results of characterization for neodymium doped yttrium aluminum garnet nanopowders - YAG:Nd3+ by the method of scanning electronic microscopy. Method. Synthesis of YAG:Nd3+ was carried out by sol-gel method from nitrate or acetate - nitrate solutions with addition of some organic compounds and ammonia as well. Such substances were used as the source ones: oxides of neodymium and yttrium with the content of the basic substance equal to 99.999 %; organic compounds: citric acid with the content of the basic substance not less than 99.0 %; ethylene glycol (99.5%; the ammonium lauryl sulfate (99.0 %; urea (99.0 % of Alfa Aesar, Fluka, Aldrich companies. Oxides of yttrium and neodymium (5 at. % were dissolved in 50% acetic acid, nitrate aluminum was added with a view to the resulting product Y2,85Nd0,15Al5,0O12, the solution was stirred and heated to 60С before reaching its transparency and uniformity. The weight of the portion corresponding to the stoichiometry YAG was 2.0 g. 50 % aqueous solutions of organic substances or 5% NH4OH in a weight ratio of 1:1 to the weight of the garnet were added in aqueous solutions, placed into glass cups. The solutions were thoroughly mixed first using a conventional stirrer, then on ultrasonic installation with simultaneous 60 С heating for 2 hours. Drying of solutions to the consistency of a powder or a thick gel was carried out at 110 С. Then the samples were placed into platinum cups and annealed in a tube furnace at 950 - 1050 С for the period from 0.5 to 2 hours. Additional annealing of the powders in the air at 950 - 1060С were carried out for the purpose of powders clarifying for residual amorphous carbon removal. Main Results. The synthesized powder precursors and powders after annealing were examined using a polarizing microscope to identify anisotropic crystalline phases. X-ray analysis of the synthesized samples was carried out on a DRON - 4 and UDR - 63

  10. Investigation of specific interactions between T7 promoter and T7 RNA polymerase by force spectroscopy using atomic force microscope.

    Science.gov (United States)

    Zhang, Xiaojuan; Yao, Zhixuan; Duan, Yanting; Zhang, Xiaomei; Shi, Jinsong; Xu, Zhenghong

    2018-01-11

    The specific recognition and binding of promoter and RNA polymerase is the first step of transcription initiation in bacteria and largely determines transcription activity. Therefore, direct analysis of the interaction between promoter and RNA polymerase in vitro may be a new strategy for promoter characterization, to avoid interference due to the cell's biophysical condition and other regulatory elements. In the present study, the specific interaction between T7 promoter and T7 RNA polymerase was studied as a model system using force spectroscopy based on atomic force microscope (AFM). The specific interaction between T7 promoter and T7 RNA polymerase was verified by control experiments, and the rupture force in this system was measured as 307.2 ± 6.7 pN. The binding between T7 promoter mutants with various promoter activities and T7 RNA polymerase was analyzed. Interaction information including rupture force, rupture distance and binding percentage were obtained in vitro , and reporter gene expression regulated by these promoters was also measured according to a traditional promoter activity characterization method in vivo Using correlation analysis, it was found that the promoter strength characterized by reporter gene expression was closely correlated with rupture force and the binding percentage by force spectroscopy. These results indicated that the analysis of the interaction between promoter and RNA polymerase using AFM-based force spectroscopy was an effective and valid approach for the quantitative characterization of promoters. © 2018 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  11. Microscopic investigation to determine the effect of Beauveria bassiana (Bals.) Vuill. and Cymbopogon citratus (DC.) Stapf. treatment on different life stages of Musca domestica (L.).

    Science.gov (United States)

    Mishra, Sapna; Kumar, Peeyush; Malik, Anushree

    2017-06-01

    Microscopic investigation was done to determine the effect of entomopathogenic fungi, Beauveria bassiana and essential oil of Cymbopogon citratus on different life stages of Musca domestica . Scanning electron microscopy investigation of fungal infected larvae showed sluggish movement, rigor, and failure of body to balance in water. Treated larvae also revealed varied level of cuticle shrinkage and extreme dehydration. Surface of B. bassiana infected pupae showed varied stage of mycelial growth, while the cadaver of adult fly was observed to have extensive fungal growth covering their entire body surface. The application of C. citratus oils on M. domestica larvae resulted in skin shrinkage, spinous cells proliferation and bleb formation, while the treated pupae showed high incidence of incomplete emergence and malformation in emerged adult flies. The current study establishes effect of C. citratus essential oil and B. bassiana infection on different life stages of M. domestica .

  12. Microscopic residual stress evolution during deformation process of an Fe---Mn---Si---Cr shape memory alloy investigated using white X-ray microbeam diffraction

    International Nuclear Information System (INIS)

    Kwon, E.P.; Sato, S.; Fujieda, S.; Shinoda, K.; Kajiwara, K.; Sato, M.; Suzuki, S.

    2013-01-01

    Microscopic residual stress evolution in different austenite (γ) grains during shape memory process in an Fe---Mn---Si---Cr alloy was investigated using the white X-ray microbeam diffraction technique. The use of high-energy white X-ray microbeam with small beam size allowed us to measure the microscopic residual stress in coarse γ grains with specific orientation. After tensile deformation large compressive residual stress was evolved in γ grains due to the formation of stress-induced ε martensite, but upon recovery heating it almost disappeared as a result of reverse transformation of martensite. The magnitude of compressive residual stress was higher in grains with orientations close to 〈144〉 and 〈233〉 orientations than in a grain with near 〈001〉 orientation. Analysis of the microstructure of each grain using electron backscattering diffraction suggested that the difference in the magnitude of compressive residual stress could be attributed to different martensitic transformation characteristics in the grains

  13. Scanning electron microscopic investigations of root structural modifications arising from growth in crude oil-contaminated sand.

    Science.gov (United States)

    Balasubramaniyam, Anuluxshy; Harvey, Patricia J

    2014-11-01

    The choice of plant for phytoremediation success requires knowledge of how plants respond to contaminant exposure, especially their roots which are instrumental in supporting rhizosphere activity. In this study, we investigated the responses of plants with different architectures represented by beetroot (Beta vulgaris), a eudicot with a central taproot and many narrower lateral roots, and tall fescue (Festuca arundinacea), a monocot possessing a mass of threadlike fibrous roots to grow in crude oil-treated sand. In this paper, scanning electron microscopy was used to investigate modifications to plant root structure caused by growth in crude oil-contaminated sand. Root structural disorders were evident and included enhanced thickening in the endodermis, increased width of the root cortical zone and smaller diameter of xylem vessels. Inhibition in the rate of root elongation correlated with the increase in cell wall thickening and was dramatically pronounced in beetroot compared to the roots of treated fescue. The latter possessed significantly fewer (p root hairs compared to control plants. Possibly, root hairs that absorb the hydrophobic contaminants may prevent contaminant absorption into the main root and concomitant axile root thickening by being sloughed off from roots. Tall fescue exhibited greater root morphological adaptability to growth in crude oil-treated sand than beetroot and, thus, a potential for long-term phytoremediation.

  14. Joule heating and spin-transfer torque investigated on the atomic scale using a spin-polarized scanning tunneling microscope.

    Science.gov (United States)

    Krause, S; Herzog, G; Schlenhoff, A; Sonntag, A; Wiesendanger, R

    2011-10-28

    The influence of a high spin-polarized tunnel current onto the switching behavior of a superparamagnetic nanoisland on a nonmagnetic substrate is investigated by means of spin-polarized scanning tunneling microscopy. A detailed lifetime analysis allows for a quantification of the effective temperature rise of the nanoisland and the modification of the activation energy barrier for magnetization reversal, thereby using the nanoisland as a local thermometer and spin-transfer torque analyzer. Both the Joule heating and spin-transfer torque are found to scale linearly with the tunnel current. The results are compared to experiments performed on lithographically fabricated magneto-tunnel junctions, revealing a very high spin-transfer torque switching efficiency in our experiments.

  15. Magnetism and site exchange in CuFeAs and CuFeSb: A microscopic and theoretical investigation

    Science.gov (United States)

    Kamusella, Sirko; Klauss, Hans-Henning; Thakur, Gohil S.; Haque, Zeba; Gupta, Laxmi C.; Ganguli, Ashok K.; Kraft, Inga; Burkhardt, Ulrich; Rosner, Helge; Luetkens, Hubertus; Lynn, Jeffrey W.; Zhao, Yang

    2017-03-01

    We have investigated the magnetic ground state of CuFeAs and CuFeSb by means of 57Fe-Mössbauer spectroscopy, muon spin rotation/relaxation (μ SR ), neutron diffraction, and electronic structure calculations. Both materials share the 111-LiFeAs crystal structure and are closely related to the class of iron-based superconductors. In both materials there is a considerable occupancy of the Cu site by Fe, which leads to ferromagnetic moments, which are magnetically strongly coupled to the regular Fe site magnetism. Our study shows that CuFeAs is close to an antiferromagnetic instability, whereas a ferromagnetic ground state is observed in CuFeSb, supporting theoretical models of anion height driven magnetism.

  16. Microscopic investigation of soot and ash particulate matter derived from biofuel and diesel: implications for the reactivity of soot

    Science.gov (United States)

    Liati, Anthi; Spiteri, Alexander; Dimopoulos Eggenschwiler, Panayotis; Vogel-Schäuble, Nina

    2012-11-01

    Investigation of soot and ash particulate matter deposited in diesel particulate filters (DPFs) operating with biofuel (B100) and diesel (pure diesel: B0 and diesel80/biofuel20 blend: B20) by means of optical microscopy, scanning electron microscopy, and high resolution transmission electron microscopy (HRTEM) reveals the following: the rapeseed methyl ester biofuel used for this study contributes to ash production, mainly of Ca-S- and P-bearing compounds ranging in size between 50 and 300 nm. Smaller ash particles are less common and build aggregates. Ash is deposited on the inlet DPF surface, the inlet channel walls, and in B100-DPF at the plugged ends of inlet channels. The presence of Fe-Cr-Ni fragments, down to tens of nanometers in size within the ash is attributed to engine wear. Pt particles (50-400 nm large) within the ash indicate that the diesel oxidation catalyst (DOC) upstream of the DPF shows aging effects. Radial cracks on the coating layer of the DOC confirm this assumption. The B100-DPF contains significantly less soot than B20 and B0. Based on the generally accepted view that soot reactivity correlates with the nanostructure of its primary particles, the length and curvature of graphene sheets from biofuel- and diesel-derived soot were measured and computed on the basis of HRTEM images. The results show that biofuel-derived soot can be more easily oxidized than diesel soot, not only during early formation but also during and after considerable particle growth. Differences in the graphene sheet separation distance, degree of crystalline order and size of primary soot particles between the two fuel types are in line with this inference.

  17. Microscopic investigation of soot and ash particulate matter derived from biofuel and diesel: implications for the reactivity of soot

    International Nuclear Information System (INIS)

    Liati, Anthi; Spiteri, Alexander; Dimopoulos Eggenschwiler, Panayotis; Vogel-Schäuble, Nina

    2012-01-01

    Investigation of soot and ash particulate matter deposited in diesel particulate filters (DPFs) operating with biofuel (B100) and diesel (pure diesel: B0 and diesel 80 /biofuel 20 blend: B20) by means of optical microscopy, scanning electron microscopy, and high resolution transmission electron microscopy (HRTEM) reveals the following: the rapeseed methyl ester biofuel used for this study contributes to ash production, mainly of Ca–S– and P-bearing compounds ranging in size between 50 and 300 nm. Smaller ash particles are less common and build aggregates. Ash is deposited on the inlet DPF surface, the inlet channel walls, and in B100-DPF at the plugged ends of inlet channels. The presence of Fe–Cr–Ni fragments, down to tens of nanometers in size within the ash is attributed to engine wear. Pt particles (50–400 nm large) within the ash indicate that the diesel oxidation catalyst (DOC) upstream of the DPF shows aging effects. Radial cracks on the coating layer of the DOC confirm this assumption. The B100-DPF contains significantly less soot than B20 and B0. Based on the generally accepted view that soot reactivity correlates with the nanostructure of its primary particles, the length and curvature of graphene sheets from biofuel- and diesel-derived soot were measured and computed on the basis of HRTEM images. The results show that biofuel-derived soot can be more easily oxidized than diesel soot, not only during early formation but also during and after considerable particle growth. Differences in the graphene sheet separation distance, degree of crystalline order and size of primary soot particles between the two fuel types are in line with this inference.

  18. Possibilities and prospects of investigation of irradiated structural and fuel materials using scanning electron microscope PHILLIPS XL 30 ESEM-TMP installed in the hot cell

    International Nuclear Information System (INIS)

    Golovanov, V. N.; Novoselov, A.E.; Kuzmin, S.V.; Yakovlev, V. V.

    2005-01-01

    Scanning electron microscope Philips XL 30 ESEM - TMP with X-ray microanalysis system INCA has been installed at SSC RF RIAR. The microscope is placed in the hot cell. Monitoring and control system is installed in the operator's room. Irradiated specimens are supplied to the hot cell through the transport terminal and installed into the microscope by manipulators. Direct contact of the personnel with radioactive materials is impossible. In addition it is developed the system of remote placement of the irradiated specimens into the specimen chamber of microscope. The system includes a stage with three seats, holders for different types of specimens and equipment for their remote loading in the holders. (Author)

  19. In vivo confocal microscopic investigation of the cornea after autologous implantation of lenticules obtained through small incision lenticule extraction for treatment of hyperopia.

    Science.gov (United States)

    Li, Meiyan; Li, Meng; Sun, Ling; Han, Tian; Ding, Lan; Xiang, Jun; Zhou, Xingtao

    2018-01-01

    To investigate re-innervation in the implanted lenticule, as well as changes to the cornea, after correcting hyperopia with an autologous implantation of a lenticule obtained through small incision lenticule extraction (SMILE). This study retrospectively analysed re-innervation in the implanted lenticule, as well as microscopic morphological changes in the corneal architecture of the recipient cornea in five patients (with myopia in one eye and hyperopia in the contralateral eye) who received SMILE in the myopic eye and femtosecond laser in situ keratomileusis (FS-LASIK) combined with lenticule implantation in the contralateral hyperopic eye. Re-innervation in the implanted lenticule, as well as microscopic morphological changes in corneal architecture, were evaluated by in vivo confocal microscopy. One patient was examined at postoperative week six, two were examined at postoperative month two, one was examined at postoperative month nine, and one was examined at postoperative month 12. Partial subbasal nerve fibre regeneration was detected in two patients (Case 4 who was examined at postoperative month nine and Case 5 who was examined at postoperative month 12). Regenerated and branched nerve fibres were detected in the implanted lenticule in Case 5 who was examined at postoperative month 12. Both the anterior and posterior interfaces showed an absence or decrease of keratocytes and the presence of small particles of various brightnesses. Keratocytes in the implanted lenticule presented abnormal morphology in size and shape after surgery in all treated eyes, but showed partial morphological recovery in two patients (Case 4 who was examined at postoperative month nine and Case 5 who was examined at postoperative month 12). These preliminary findings suggest that nerve fibres will regenerate into the implanted lenticule after autologous lenticule implantation. Keratocytes in lenticules demonstrated a gradual return to a normal morphology. © 2017 Optometry

  20. Microscopic examination of deteriorated concrete

    NARCIS (Netherlands)

    Nijland, T.G.; Larbi, J.A.

    2010-01-01

    Concrete petrography is the integrated microscopic and mesoscale (hand specimen size) investigation of hardened concrete, that can provide information on the composition of concrete, the original relationships between the concrete's various constituents, and any changes therein, whether as a result

  1. Ultrafast supercontinuum fiber-laser based pump-probe scanning magneto-optical Kerr effect microscope for the investigation of electron spin dynamics in semiconductors at cryogenic temperatures with picosecond time and micrometer spatial resolution.

    Science.gov (United States)

    Henn, T; Kiessling, T; Ossau, W; Molenkamp, L W; Biermann, K; Santos, P V

    2013-12-01

    We describe a two-color pump-probe scanning magneto-optical Kerr effect microscope which we have developed to investigate electron spin phenomena in semiconductors at cryogenic temperatures with picosecond time and micrometer spatial resolution. The key innovation of our microscope is the usage of an ultrafast "white light" supercontinuum fiber-laser source which provides access to the whole visible and near-infrared spectral range. Our Kerr microscope allows for the independent selection of the excitation and detection energy while avoiding the necessity to synchronize the pulse trains of two separate picosecond laser systems. The ability to independently tune the pump and probe wavelength enables the investigation of the influence of excitation energy on the optically induced electron spin dynamics in semiconductors. We demonstrate picosecond real-space imaging of the diffusive expansion of optically excited electron spin packets in a (110) GaAs quantum well sample to illustrate the capabilities of the instrument.

  2. Does the extracorporeal circulation worsen anemia in hemodialysis patients? Investigation with advanced microscopes of red blood cells drawn at the beginning and end of dialysis.

    Science.gov (United States)

    Stamopoulos, Dimosthenis; Bakirtzi, Nerantzoula; Manios, Efthymios; Grapsa, Eirini

    2013-01-01

    In hemodialysis (HD) patients, anemia relates to three main factors: insufficient production of erythropoietin; impaired management of iron; and decreased lifespan of red blood cells (RBCs). The third factor can relate to structural deterioration of RBCs due to extrinsic (extracorporeal circuit; biochemical activation and/or mechanical stress during dialysis) and intrinsic (uremic milieu; biochemical interference of the RBC membrane constituents with toxins) mechanisms. Herein, we evaluate information accessed with advanced imaging techniques at the cellular level. Atomic force and scanning electron microscopes were employed to survey intact RBCs (iRBCs) of seven HD patients in comparison to seven healthy donors. The extrinsic factor was investigated by contrasting pre- and post-HD samples. The intrinsic environment was investigated by comparing the microscopy data with the clinical ones. The iRBC membranes of the enrolled HD patients were overpopulated with orifice-like (high incidence; typical size within 100-1,000 nm) and crevice-like (low incidence; typical size within 500-4,000 nm) defects that exhibited a statistically significant (P < 0.05) relative increase (+55% and +350%, respectively) in respect to healthy donors. The relative variation of the orifice and crevice indices (mean population of orifices and crevices per top membrane surface) between pre- and post-HD was not statistically significant (-3.3% and +4.5%, respectively). The orifice index correlates with the concentrations of urea, calcium, and phosphorus, but not, however, with that of creatinine. Extracorporeal circulation is not detrimental to the structural integrity of RBC membranes. Uremic milieu is a candidate cause of RBC membrane deterioration, which possibly worsens anemia.

  3. Microscopic approach to polaritons

    DEFF Research Database (Denmark)

    Skettrup, Torben

    1981-01-01

    The interaction between excitons and light has been investigated in detail. The perturbational approach turns out to be invalid. However, an exact solution can be obtained directly from the Schrödinger equation for a fixed light field. This solution corresponds to a nonlinear optical response...... contrary to experimental experience. In order to remove this absurdity the semiclassical approach must be abandoned and the electromagnetic field quantized. A simple microscopic polariton model is then derived. From this the wave function for the interacting exciton-photon complex is obtained...... of light of the crystal. The introduction of damping smears out the excitonic spectra. The wave function of the polariton, however, turns out to be very independent of damping up to large damping values. Finally, this simplified microscopic polariton model is compared with the exact solutions obtained...

  4. [Scanning electron microscopic investigations of cutting edge quality in lamellar keratotomy using the Wavelight femtosecond laser (FS-200) : What influence do spot distance and an additional tunnel have?

    Science.gov (United States)

    Hammer, T; Höche, T; Heichel, J

    2018-01-01

    Femtosecond lasers (fs-lasers) are established cutting instruments for the creation of LASIK flaps. Previous studies often showed even rougher surfaces after application of fs-laser systems compared to lamellar keratotomy with mechanical microkeratomes. When cutting the cornea with fs-lasers, an intrastromal gas development occurs, which has a potentially negative influence on the cutting quality if the gas cannot be dissipated; therefore, manufacturers have chosen the way of gas assimilation in so-called pockets. The investigated system creates a tunnel which opens under the conjunctiva. The aim of this study was to investigate the effects of a tunnel as well as the influence of different spot distances on the quality of cut surfaces and edges. In this experimental study on freshly enucleated porcine eyes (n = 15), the following cuts were carried out with the FS-200 (Wavelight, Erlangen, Germany): 1. standard setting (spot and line separation 8 µm), 2. with tunnel for gas drainage, 3. without gas-conducting tunnel, 4. with increased spot spacing (spot and line separation 9 μm instead of 8 μm) and 5. with reduced spot spacing (spot and line separation 7 μm instead of 8 μm). Subsequently, scanning electron microscopy (FEI Quanta 650, Hillsboro, OR) of the cut edges and surfaces as well as the gas drain tunnel were performed. The evaluation was based on an established score. The current fs-laser system (200 Hz) is able to create smooth cutting surfaces and sharp edges. The changed density of laser pulses compared to the standard settings with a reduced or increased distance between the pulses, did not achieve any further improvement in the surface quality. The gas-conducting tunnel could be detected by scanning electron microscope. In the case of cutting without a tunnel, roughened surfaces and irregularities on the cutting edges were found. When the FS-200 fs-laser is used, LASIK cuts with very smooth cut surfaces and sharp cutting

  5. A modular designed ultra-high-vacuum spin-polarized scanning tunneling microscope with controllable magnetic fields for investigating epitaxial thin films.

    Science.gov (United States)

    Wang, Kangkang; Lin, Wenzhi; Chinchore, Abhijit V; Liu, Yinghao; Smith, Arthur R

    2011-05-01

    A room-temperature ultra-high-vacuum scanning tunneling microscope for in situ scanning freshly grown epitaxial films has been developed. The core unit of the microscope, which consists of critical components including scanner and approach motors, is modular designed. This enables easy adaptation of the same microscope units to new growth systems with different sample-transfer geometries. Furthermore the core unit is designed to be fully compatible with cryogenic temperatures and high magnetic field operations. A double-stage spring suspension system with eddy current damping has been implemented to achieve ≤5 pm z stability in a noisy environment and in the presence of an interconnected growth chamber. Both tips and samples can be quickly exchanged in situ; also a tunable external magnetic field can be introduced using a transferable permanent magnet shuttle. This allows spin-polarized tunneling with magnetically coated tips. The performance of this microscope is demonstrated by atomic-resolution imaging of surface reconstructions on wide band-gap GaN surfaces and spin-resolved experiments on antiferromagnetic Mn(3)N(2)(010) surfaces.

  6. Investigation of voltages and electric fields in silicon semi 3D radiation detectors using Silvaco/ATLAS simulation tool and a scanning electron microscope

    CERN Document Server

    Palviainen, T; Tuuva, T; Eranen, S; Härkönen, J; Luukka, P; Tuovinen, E

    2006-01-01

    The structure of silicon semi three-dimensional radiation detector is simulated on purpose to find out its electrical characteristics such as the depletion voltage and electric field. Two-dimensional simulation results are compared to voltage and electric field measurements done by a scanning electron microscope.

  7. X-ray microscopes at BESSY II

    International Nuclear Information System (INIS)

    Guttmann, P.; Niemann, B.; Thieme, J.; Wiesemann, U.; Rudolph, D.; Schmahl, G.

    2000-01-01

    The undulator U41 at BESSY II will be used as source for X-ray microscopes. An overview of the X-ray microscopy area is presented. After finishing the construction phase a transmission X-ray microscope, a scanning transmission X-ray microscope and an X-ray test chamber will be available. The transmission X-ray microscope will allow investigations with high lateral resolution at moderate energy resolution while the scanning transmission X-ray microscope will allow high energy resolution at moderate lateral resolution of the same specimen

  8. Imaging of radiation damage using complementary field ion microscopy and atom probe tomography

    International Nuclear Information System (INIS)

    Dagan, Michal; Hanna, Luke R.; Xu, Alan; Roberts, Steve G.; Smith, George D.W.; Gault, Baptiste; Edmondson, Philip D.; Bagot, Paul A.J.; Moody, Michael P.

    2015-01-01

    Radiation damage in tungsten and a tungsten–tantalum alloy, both of relevance to nuclear fusion research, has been characterized using a combination of field ion microscopy (FIM) imaging and atom probe tomography (APT). While APT provides 3D analytical imaging with sub-nanometer resolution, FIM is capable of imaging the arrangements of single atoms on a crystal lattice and has the potential to provide insights into radiation induced crystal damage, all the way down to its smallest manifestation – a single vacancy. This paper demonstrates the strength of combining these characterization techniques. In ion implanted tungsten, it was found that atomic scale lattice damage is best imaged using FIM. In certain cases, APT reveals an identifiable imprint in the data via the segregation of solute and impurities and trajectory aberrations. In a W–5 at%Ta alloy, a combined APT–FIM study was able to determine the atomic distribution of tantalum inside the tungsten matrix. An indirect method was implemented to identify tantalum atoms inside the tungsten matrix in FIM images. By tracing irregularities in the evaporation sequence of atoms imaged with FIM, this method enables the benefit of FIM's atomic resolution in chemical distinction between the two species. - Highlights: • Complementary FIM and APT was used to study nanoscale radiation damage in tungsten. • Trajectory aberrations in APT revealed extended lattice damage which FIM confirmed. • Nano scale features were detected indirectly with APT via segregation of impurities. • Induced damage at the scale of a single vacancy could only be detected via FIM. • 3DFIM characterized W–5Ta atomic distribution with improved detection efficiency.

  9. Transmission positron microscopes

    International Nuclear Information System (INIS)

    Doyama, Masao; Kogure, Yoshiaki; Inoue, Miyoshi; Kurihara, Toshikazu; Yoshiie, Toshimasa; Oshima, Ryuichiro; Matsuya, Miyuki

    2006-01-01

    Immediate and near-future plans for transmission positron microscopes being built at KEK, Tsukuba, Japan, are described. The characteristic feature of this project is remolding a commercial electron microscope to a positron microscope. A point source of electrons kept at a negative high voltage is changed to a point source of positrons kept at a high positive voltage. Positional resolution of transmission microscopes should be theoretically the same as electron microscopes. Positron microscopes utilizing trapping of positrons have always positional ambiguity due to the diffusion of positrons

  10. The Scanning Optical Microscope.

    Science.gov (United States)

    Sheppard, C. J. R.

    1978-01-01

    Describes the principle of the scanning optical microscope and explains its advantages over the conventional microscope in the improvement of resolution and contrast, as well as the possibility of producing a picture from optical harmonies generated within the specimen.

  11. Forensic Scanning Electron Microscope

    Science.gov (United States)

    Keeley, R. H.

    1983-03-01

    The scanning electron microscope equipped with an x-ray spectrometer is a versatile instrument which has many uses in the investigation of crime and preparation of scientific evidence for the courts. Major applications include microscopy and analysis of very small fragments of paint, glass and other materials which may link an individual with a scene of crime, identification of firearms residues and examination of questioned documents. Although simultaneous observation and chemical analysis of the sample is the most important feature of the instrument, other modes of operation such as cathodoluminescence spectrometry, backscattered electron imaging and direct x-ray excitation are also exploited. Marks on two bullets or cartridge cases can be compared directly by sequential scanning with a single beam or electronic linkage of two instruments. Particles of primer residue deposited on the skin and clothing when a gun is fired can be collected on adhesive tape and identified by their morphology and elemental composition. It is also possible to differentiate between the primer residues of different types of ammunition. Bullets may be identified from the small fragments left behind as they pass through the body tissues. In the examination of questioned documents the scanning electron microscope is used to establish the order in which two intersecting ink lines were written and to detect traces of chemical markers added to the security inks on official documents.

  12. Crystal structure and defects of Zr4Co4Si7( V-phase) investigated by high resolution transmission electron microscope

    International Nuclear Information System (INIS)

    Mao, J.F.; Ye, H.Q.; Ning, X.G.; He, L.L.; Yang, D.Z.

    1997-01-01

    The results of high resolution transmission electron microscope (HRTEM) observation and image simulation show that Zr 4 Co 4 Si 7 possesses the same structure type of Zr 4 Co 4 Ge 7 . Adding of Fe or Ni into the Zr 4 Co 4 Si 7 compound, except that the dimensions changed slightly, does not change the lattice type and coordination in the crystal structure, maintaining the V-phase structure. Also, twins with coherent boundaries and with partially coherent at interfaces are observed. The image conditions of Zr 4 Co 4 Si 7 and the structure differences between Zr 4 Co 4 Si 7 and tetrahedral close-packed phases are also discussed. copyright 1997 Materials Research Society

  13. Cryogenic immersion microscope

    Science.gov (United States)

    Le Gros, Mark; Larabell, Carolyn A.

    2010-12-14

    A cryogenic immersion microscope whose objective lens is at least partially in contact with a liquid reservoir of a cryogenic liquid, in which reservoir a sample of interest is immersed is disclosed. When the cryogenic liquid has an index of refraction that reduces refraction at interfaces between the lens and the sample, overall resolution and image quality are improved. A combination of an immersion microscope and x-ray microscope, suitable for imaging at cryogenic temperatures is also disclosed.

  14. Binding of the transcription activator NRI (NTRC) to a supercoiled DNA segment imitates association with the natural enhancer: an electron microscopic investigation.

    Science.gov (United States)

    Révet, B; Brahms, S; Brahms, G

    1995-08-01

    Electron microscopic visualization indicates that the transcription activator NRI (NTRC) binds with exceptional selectivity and efficiency to a sequence-induced superhelical (spiral) segment inserted upstream of the glnA promoter, accounting for its observed ability to substitute for the natural glnA enhancer. The cooperative binding of NRI to the spiral insert leads to protein oligomerization which, at higher concentration, promotes selective coating of the entire superhelical segment with protein. Localization of NRI at apical loops is observed with negatively supercoiled plasmid DNA. With a linear plasmid, bending of DNA is observed. We confirm that NRI is a DNA-bending protein, consistent with its high affinity for spiral DNA. These results prove that spiral DNA without any homology to the NRI-binding sequence site can substitute for the glnA enhancer by promoting cooperative activator binding to DNA and facilitating protein oligomerization. Similar mechanisms might apply to other prokaryotic and eukaryotic activator proteins that share the ability to bend DNA and act efficiently as multimers.

  15. Mechanism of the transition from orthorhombic to tetragonal YBa 2Cu 3O 7- x. Investigation of a reversible topotactic reaction in the electron microscope

    Science.gov (United States)

    Müller, J.-H.; Gruehn, R.

    The phase transition from orthorhombic to tetragonal could be observed (in situ) with High-Resolution Transmission Electron Microscopy (HRTEM). In superconducting samples of YBa 2Cu 3O 7- x ( x=0.09) twinned areas were found which changed from orthorhombic to tetragonal symmetry upon electron irradiation parallel to the long c axis. In opposition to annealing experiments the length of the c-axis remained unchanged. The transition was reversible in the high vacuum of the electron microscope. Therefore we surmise that this reaction has no reductive character (no perceptible loss of oxygen). Within the tetragonal structure one can assume a statistical sharing (“disorder”) of oxygen by the metal atoms. The transition could also be explained by a migration of oxygen to the surface. After finishing the irradiation experiment and waiting for several minutes, the oxygen seems to occupy partially ordered positions resulting again in an orthorhombic symmetry. In some cases we could observed transition states of the structural transformation. A schematic model of the mechanism is depicted.

  16. Investigation of the effects of aluminum stress on some macro and micro-nutrient contents of the seedlings of lycopersicon esculentum mill. by using scanning electron microscope

    International Nuclear Information System (INIS)

    Colak, G.; Catak, E.; Baykul, M.C.

    2014-01-01

    This study was planned to see the affect of aluminum stress on plant nutrition and metabolism. The effects of aluminum stress on uptake level of some macro- and micro-nutrients from the nutrition solution into the seedlings of Lycopersicon esculentum Mill. and on mobilization of some nutrient elements in the seedlings were examined at the level of epidermal cells. The elemental structure of root, hypocotyl and cotyledon epidermal cells were determined by Energy Dispersive Xray Microanalysis (EDX) performed in a local area 50 nm in diameter at the level of a single epidermal cell cytoplasm by using low vacuum (24 pascal ) Scanning Electron Microscope. EDX analysis revealed that aluminum content of the cells was increasing with the increased concentrations of aluminum in the nutrient solution and that aluminum largelyaccumulated in the roots. Aluminum concentration was much higher in the root epidermal cells of the seedlings incubated in aluminum containing media for 17 days without adding any nutrient solution; it was also true for the local EDX analysis of radicle epidermal cells from the same series. Aluminum stress was found to tend to modify the plant nutritional element content of the cells and this was particularly of critical importance in terms of some macro- and micro-nutrients. The assessments performed at the level of epidermal cells of young seedlings of Lycopersicon esculentum suggest that aluminum stress leads to an absolute change in the plant nutritional element composition of the cells and in the mobilization of some nutritional elements in the seedlings. (author)

  17. Scanning Color Laser Microscope

    Science.gov (United States)

    Awamura, D.; Ode, T.; Yonezawa, M.

    1988-01-01

    A confocal color laser microscope which utilizes a three color laser light source (Red: He-Ne, Green: Ar, Blue: Ar) has been developed and is finding useful applications in the semiconductor field. The color laser microscope, when compared to a conventional microscope, offers superior color separation, higher resolution, and sharper contrast. Recently some new functions including a Focus Scan Memory, a Surface Profile Measurement System, a Critical Dimension Measurement system (CD) and an Optical Beam Induced Current Function (OBIC) have been developed for the color laser microscope. This paper will discuss these new features.

  18. Analytical Electron Microscope

    Data.gov (United States)

    Federal Laboratory Consortium — The Titan 80-300 is a transmission electron microscope (TEM) equipped with spectroscopic detectors to allow chemical, elemental, and other analytical measurements to...

  19. Comparative study of image contrast in scanning electron microscope and helium ion microscope.

    Science.gov (United States)

    O'Connell, R; Chen, Y; Zhang, H; Zhou, Y; Fox, D; Maguire, P; Wang, J J; Rodenburg, C

    2017-12-01

    Images of Ga + -implanted amorphous silicon layers in a 110 n-type silicon substrate have been collected by a range of detectors in a scanning electron microscope and a helium ion microscope. The effects of the implantation dose and imaging parameters (beam energy, dwell time, etc.) on the image contrast were investigated. We demonstrate a similar relationship for both the helium ion microscope Everhart-Thornley and scanning electron microscope Inlens detectors between the contrast of the images and the Ga + density and imaging parameters. These results also show that dynamic charging effects have a significant impact on the quantification of the helium ion microscope and scanning electron microscope contrast. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

  20. The Light Microscope.

    Science.gov (United States)

    Baker, W. L.

    1995-01-01

    Describes the function of the various parts of the microscope and their integration in the formation of an optical image. Presents a procedure for setting up a microscope to obtain maximum resolution and contrast for each objective lens at all magnifications. (JRH)

  1. Mailing microscope slides

    Science.gov (United States)

    Many insects feed agriculturally important crops, trees, and ornamental plants and cause millions of dollars of damage annually. Identification for some of these require the preparation of a microscope slide for examination. There are times when a microscope slide may need to be sent away to a speci...

  2. Origin of the inertial deviation from Darcy's law: An investigation from a microscopic flow analysis on two-dimensional model structures

    Science.gov (United States)

    Agnaou, Mehrez; Lasseux, Didier; Ahmadi, Azita

    2017-10-01

    Inertial flow in porous media occurs in many situations of practical relevance among which one can cite flows in column reactors, in filters, in aquifers, or near wells for hydrocarbon recovery. It is characterized by a deviation from Darcy's law that leads to a nonlinear relationship between the pressure drop and the filtration velocity. In this work, this deviation, also known as the nonlinear, inertial, correction to Darcy's law, which is subject to controversy upon its origin and dependence on the filtration velocity, is studied through numerical simulations. First, the microscopic flow problem was solved computationally for a wide range of Reynolds numbers up to the limit of steady flow within ordered and disordered porous structures. In a second step, the macroscopic characteristics of the porous medium and flow (permeability and inertial correction tensors) that appear in the macroscale model were computed. From these results, different flow regimes were identified: (1) the weak inertia regime where the inertial correction has a cubic dependence on the filtration velocity and (2) the strong inertia (Forchheimer) regime where the inertial correction depends on the square of the filtration velocity. However, the existence and origin of those regimes, which depend also on the microstructure and flow orientation, are still not well understood in terms of their physical interpretations, as many causes have been conjectured in the literature. In the present study, we provide an in-depth analysis of the flow structure to identify the origin of the deviation from Darcy's law. For accuracy and clarity purposes, this is carried out on two-dimensional structures. Unlike the previous studies reported in the literature, where the origin of inertial effects is often identified on a heuristic basis, a theoretical justification is presented in this work. Indeed, a decomposition of the convective inertial term into two components is carried out formally allowing the

  3. Field ion microscopy and 3-D atom probe analysis of Al3Zr particles in 7050 Al alloy

    International Nuclear Information System (INIS)

    Sha, G.; Cerezo, A.

    2004-01-01

    Full text: For high strength 7xxx series Al alloys, Zr is an important trace alloy element which is often added to optimise properties, having effects such as refining grain size, inhibiting recrystallization, and improving stress corrosion cracking resistance and quench sensitivity. In addition, it has been reported recently that Zr addition also has a significant influence on early stage ageing behaviour of a 7xxx series Al alloy. Zr equilibrium solubility in solid Al is extremely low. After solution or ageing treatment, most Zr is present as small spherical Ai 3 Zr dispersoids approximately 20 nm in diameter, distributed at grain boundaries as well as within the Al matrix. The crystallographic nature of intermetallic phase Al 3 Zr has been well studied in the literatures. So far, no direct measurement of the chemistry of the Al 3 Zr particles in 7xxx series Al alloys has been published. It is unclear if there is significant Zn, Mg or Cu included in the particles. In this research, 3DAP has been employed for the first time to investigate ionisation behaviour of Al 3 Zr particles and determine the chemistry of the particles in 7050 Al alloy. Using field ion microscopy, the local evaporation radius of the Al 3 Zr particle has been measured to be equivalent to 36 nm for a 10 kV tip, less than the equivalent tip radius for the Al matrix of ∼68 nm. Using the matrix Al evaporation field (19 V/nm) as a reference, this allows the evaporation field of Al 3 Zr to be calculated as 35 V/nm, the same as the field calculated for evaporation of Al as Al 2+ (35 V/nm), and that of Zr as Zr 3+ (35 V/nm). This result is consistent with Al 2+ and Zr 3+ being the main species observed in the mass spectrum during analysis of Al 3 Zr particles. Using 3DAP, the chemical compositions of Al 3 Zr particles are determined to be 64.8∼67.7 at% Al, 23.6∼24.8 at% Zr, 6.9∼9.1 at% Zn, 0.4∼0.7 at% Cu, 0.5∼1.2 at% Mg, with a (Al+Zn)/Zr ratio close to 3. Choice of specimen temperature of

  4. Investigation of Changes in the Microscopic Structure of Anionic Poly(N-isopropylacrylamide-co-Acrylic acid) Microgels in the Presence of Cationic Organic Dyes toward Precisely Controlled Uptake/Release of Low-Molecular-Weight Chemical Compound.

    Science.gov (United States)

    Kureha, Takuma; Shibamoto, Takahisa; Matsui, Shusuke; Sato, Takaaki; Suzuki, Daisuke

    2016-05-10

    Changes in a microscopic structure of an anionic poly(N-isopropylacrylamide-co-acrylic acid) microgel were investigated using small- and wide-angle X-ray scattering (SWAXS). The scattering profiles of the microgels were analyzed in a wide scattering vector (q) range of 0.07 ≤ q/nm(-1) ≤ 20. In particular, the microscopic structure of the microgel in the presence of a cationic dye rhodamine 6G (R6G) was characterized in terms of its correlation length (ξ), which represents the length scale of the spatial correlation of the network density fluctuations, and characteristic distance (d*), which originated from the local packing of isopropyl groups of two neighboring chains. In the presence of cationic R6G, ξ exhibited a divergent-like behavior, which was not seen in the absence of R6G, and d* was decreased with decreasing the volume of the microgel upon increasing temperature. At the same time, the amount of R6G adsorbed per unit mass of the microgel increased upon heating. These results suggested that a coil-to-globule transition of the poly(N-isopropylacrylamide) chains in the present anionic microgel occurred because of efficiently screened, thus, short ranged electrostatic repulsion between the charged groups, and hydrophobic interaction between the isopropyl groups in the presence of cationic R6G. The combination of hydrophobic and electrostatic interaction between the cationic dye and the microgel affected the separation and volume transition behavior of the microgel.

  5. Assessment of Petrological Microscopes.

    Science.gov (United States)

    Mathison, Charter Innes

    1990-01-01

    Presented is a set of procedures designed to check the design, ergonomics, illumination, function, optics, accessory equipment, and image quality of a microscope being considered for purchase. Functions for use in a petrology or mineralogy laboratory are stressed. (CW)

  6. Scanning Auger Electron Microscope

    Data.gov (United States)

    Federal Laboratory Consortium — A JEOL model 7830F field emission source, scanning Auger microscope.Specifications / Capabilities:Ultra-high vacuum (UHV), electron gun range from 0.1 kV to 25 kV,...

  7. Investigation of Opioid Growth Factor Pathway Inhibition on the Histologic Structure of Testicular Tissue and Microscopic Indices of Spermatogenesis in Adult Diabetic Mice

    Directory of Open Access Journals (Sweden)

    Razi Davoud Khar

    2017-03-01

    Full Text Available Background and aims: Endogenous opioids function as negative factors affecting the growth has been established. The most influential factor in the growth and differentiation of the proliferating cells is the opioid growth factor (OGF. Recently, some studies have been completed about the effects of opioid growth factor in the pathogenesis of diabetes and the beneficial effects of inhibition of this growth pathway have been demonstrated. The aim of this study was to investigate the effect of inhibition of opioids growth pathway, in proliferation and growth of testicular germ cells and spermatogenesis following experimental diabetes in adult mice.

  8. Application of analytical electron microscopic methods to investigate the function of spherites in the midgut of the larval antlion Euroleon nostras (Neuroptera: Myrmeleontidae).

    Science.gov (United States)

    Lipovšek, Saška; Letofsky-Papst, Ilse; Hofer, Ferdinand; Pabst, Maria Anna; Devetak, Dušan

    2012-04-01

    This study presents an application of analytical electron microscopy in biology to investigate the chemical composition of the spherites and to elucidate the importance of these methods in the life sciences. The structure of the spherites in the midgut cells of first, second, and third instar larvae Euroleon nostras was investigated by a combination of transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDXS), electron energy-loss spectroscopy (EELS), and energy filtering TEM (EFTEM). The structure and chemical composition of the spherites changed during the metamorphosis. In first larvae, the spherites are composed of amorphous, flocculent material, containing C, N, and O. In second larvae and third ones, the spherites have concentric layers of alternating electron-dense and electron-lucent material. In second larvae, Si, P, Ca, and Fe are accumulated in the spherite organic matrix, composed of C, N, and O. In the spherites of third larvae, additionally Al was found. Therefore, the spherites are thought to store organic compounds in all three larval stages of E. nostras and additionally inorganic compounds in second and third ones. In first larvae, spherites are present in the midgut cells; in second and third larvae, they are present in the cells of the midgut and in its lumen. It could be suggested that the spherites might be involved in the regulation of the appropriate mineral composition of the internal environment and could serve as the accumulation site of nontoxic waste materials that cannot be metabolized. Copyright © 2011 Wiley-Liss, Inc.

  9. Applying a Commercial Atomic Force Microscope for Scanning Near-field Optical Microscopy Techniques and Investigation of Cell-cell Signaling

    Science.gov (United States)

    Lopez Ayon, Gabriela Monserratt

    The field of research of this thesis is Condensed Matter Physics applied to Biology. Specifically it describes the development of different Atomic Force Microscopy techniques and tools towards the study of living cells in physiological solution. Particular interest is put into the understanding of the influence of noise in the determination of ordered liquid layers above a mica surface - as work towards the study of the role of water and ions in biological processes - and the influence of "diving bell" to boost the Q factor and allow stable imaging and force spectroscopy with tips based on Scanning Near-field Optical Microscopy [LeDue, 2010 and LeDue, 2008]. By combining SNOM techniques as a local illumination method (and thus avoiding photo bleaching of individual molecules) and high resolution AFM techniques we will be able to investigate mechano-transduction and associated signaling in living cells and individual proteins.

  10. Co-sequestration of Zn(II) and phosphate by γ-Al2O3: From macroscopic to microscopic investigation

    International Nuclear Information System (INIS)

    Ren, Xuemei; Tan, Xiaoli; Hayat, Tasawar; Alsaedi, Ahmed; Wang, Xiangke

    2015-01-01

    Highlights: • How the Zn and phosphate behave in each other’s presence is elucidated. • Surface speciation of Zn(II) is affected by the presence of phosphate. • Combining macroscopic study with EXAFS can determine the Zn(II) surface speciation. • The enhanced Zn(II) sorption is mainly due to ternary surface complexation at 0.19 mmol P/L and pH 6.5. • Phosphate ions prevent the formation of an Zn–Al LDH phase at pH 8.0. - Abstract: Little information is available concerning co-sorbing oxyanion and metal contaminants in the environment, yet in most metal-contaminated areas, co-contamination by phosphate is common. In this study, the mutual effects of phosphate and Zn(II) on their interaction with γ-Al 2 O 3 are investigated by batch experiments and X-ray absorption fine structure spectroscopy (XAFS) technique. The results show that the co-sorption of phosphate on γ-Al 2 O 3 modifies both the extent of Zn(II) sorption and the local atomic structures of sorbed Zn(II) ions. Multiple mechanisms are involved in Zn(II) retention in the presence of phosphate, including electrostatic interaction, binary and ternary surface complexation, and the formation of Zn(II)-phosphate polynuclear complexes. At pH 6.5, type III ternary surface complexation occurs concurrently with binary Zn-alumina surface complexation at low phosphate concentrations, whereas the formation of type III ternary surface complexes is promoted as the phosphate concentration increases. With further increasing phosphate concentration, Zn(II)-phosphate polynuclear complexes are formed. At pH 8.0, Zn dominantly forms type III ternary surface complexes in the presence of phosphate. The results of this study indicate the variability of Zn complexation on oxide surface and the importance of combining macroscopic observations with XAFS capable of determining metal complex formation mechanism for ternary system

  11. Does sudden unexplained nocturnal death syndrome remain the autopsy negative disorder: a gross, microscopic, and molecular autopsy investigation in Southern China

    Science.gov (United States)

    Zhang, Liyong; Tester, David J.; Lang, Di; Chen, Yili; Zheng, Jinxiang; Gao, Rui; Corliss, Robert F.; Tang, Shuangbo; Kyle, John W.; Liu, Chao; Ackerman, Michael J.; Makielski, Jonathan C.; Cheng, Jianding

    2016-01-01

    Objective To look for previously unrecognized cardiac structural abnormalities and address the genetic cause for sudden unexplained nocturnal death syndrome (SUNDS). Methods and Results 148 SUNDS victims and 444 controls (matched 1:3 on gender, race, and age of death within 1 year) were collected from Sun Yat-sen University from January 1, 1998 to December 31, 2014 to search morphological changes. Additional 17 Brugada syndrome (BrS) patients collected from January 1, 2006 to December 31, 2014 served as a comparative disease cohort. The Target Captured Next Generation sequencing for 80 genes associated with arrhythmia/cardiomyopathy were performed in 44 SUNDS victims and 17 BrS patients to characterize the molecular spectrum. SUNDS had slight but statistically significantly increased heart weight and valve circumference compared to controls. 12/44 SUNDS victims (SCN5A, SCN1B, CACNB2, CACNA1C, AKAP9, KCNQ1, KCNH2, KCNJ5, GATA4, NUP155, ABCC9) and 6/17 BrS patients (SCN5A, CACNA1C, P>.05) carried rare variants in primary arrhythmia-susceptibility genes. Only 2/44 SUNDS cases compared to 5/17 BrS patients hosted a rare variant in the most common BrS causing gene, SCN5A (P=.01). Using the strict American College of Medical Genetics guideline-based definition, only 2/44 (KCNQ1) SUNDS and 3/17 (SCN5A) BrS patients hosted a “(likely) pathogenic” variant. The 14/44 SUNDS cases with cardiomyopathy-related variants had a subtle but significantly decreased circumference of cardiac valves, and tended to die on average 5–6 years younger compared to the remaining 30 cases (P=.02). Conclusions We present the first comprehensive autopsy evidence that SUNDS victims may have concealed cardiac morphological changes. SUNDS and BrS may result from different molecular pathological underpinnings. The distinct association between cardiomyopathy-related rare variants and SUNDS warrants further investigation. PMID:27707468

  12. A Hybrid Constant and Oscillatory Field Ion Mobility Analyzer Using Structures for Lossless Ion Manipulations

    Science.gov (United States)

    Prabhakaran, Aneesh; Hamid, Ahmed M.; Garimella, Sandilya V. B.; Valenzuela, Blandina R.; Ewing, Robert G.; Ibrahim, Yehia M.; Smith, Richard D.

    2018-02-01

    Here we explore the combination of constant and oscillatory fields applied in a single device to affect the continuous separation and filtering of ions based on their mobilities. The device explored allows confining and manipulating ions utilizing a combination of radio frequency (rf), direct current (DC) fields, and traveling waves (TW) in a structures for lossless ion manipulations (SLIM) module. We have investigated theoretically and experimentally a concept for continuous filtering of ions based on their mobilities where ions are mobility separated and selected by passage through two regions, both of which incorporated combined TW and constant fields providing opposing forces on the ions. The SLIM module was composed of two surfaces with mirror-image arrays of electrodes and had two regions where the different TW and opposing DC fields could be applied. The filtering capabilities are determined by the applied DC gradient and the TW parameters, such as speed, amplitude, and the TW sequence (i.e., the duty cycle of the traveling wave). The effects of different parameters on the sensitivity and the ion mobility (IM) resolution of the device have been investigated. By appropriately choosing the DC gradient and TW parameters for the two sections, it is possible to transmit ions of a selected mobility while filtering out others of both higher and lower mobility. The novel device described here provides a basis for the targeted analysis of compounds based upon the continuous selection of ions according to their mobility and without the need for high electric fields or pulsed injection.

  13. Electron microscope studies

    Energy Technology Data Exchange (ETDEWEB)

    Crewe, A.V.; Kapp, O.H.

    1992-07-01

    This is a report covering the research performed in the Crewe laboratory between 1964 and 1992. Because of limitations of space we have provided relatively brief summaries of the major research directions of the facility during these years. A complete bibliography has been included and we have referenced groups of pertinent publications at the beginning of each section. This report summarizes our efforts to develop better electron microscopes and chronicles many of the experimental programs, in materials science and biology, that acted both as a stimulus to better microscope design and also as a testing ground for many instrumental innovations.

  14. Electron microscope studies

    International Nuclear Information System (INIS)

    Crewe, A.V.; Kapp, O.H.

    1992-01-01

    This is a report covering the research performed in the Crewe laboratory between 1964 and 1992. Because of limitations of space we have provided relatively brief summaries of the major research directions of the facility during these years. A complete bibliography has been included and we have referenced groups of pertinent publications at the beginning of each section. This report summarizes our efforts to develop better electron microscopes and chronicles many of the experimental programs, in materials science and biology, that acted both as a stimulus to better microscope design and also as a testing ground for many instrumental innovations

  15. Microscopic investigation of surface layers on rails

    Czech Academy of Sciences Publication Activity Database

    Jirásková, Yvonna; Svoboda, Jiří; Schneeweiss, Oldřich; Daves, W.; Fischer, F. D.

    2005-01-01

    Roč. 239, č. 2 (2005), s. 132-141 ISSN 0169-4332 R&D Projects: GA AV ČR(CZ) IBS2041105 Institutional research plan: CEZ:AV0Z20410507 Keywords : Mössbauer phase analysis * TEM * rail Subject RIV: JO - Structural Engineering Impact factor: 1.263, year: 2005

  16. Scanning transmission electron microscope

    NARCIS (Netherlands)

    Kruit, P.

    2006-01-01

    The invention relates to a scanning transmission electron microscope comprising an electron source, an electron accelerator and deflection means for directing electrons emitted by the electron source at an object to be examined, and in addition a detector for detecting electrons coming from the

  17. MICROSCOPIC, PHYSICOCHEMICAL AND CHROMATOGRAPHIC ...

    African Journals Online (AJOL)

    Peters

    MICROSCOPIC, PHYSICOCHEMICAL AND CHROMATOGRAPHIC. FINGERPRINTS OF LEAVES OF NIGERIAN CASSIA TORA LINN. Fatokun Omolola T1*., EsievoKevwe B2., Ugbabe Grace E3. and Kunle Oluyemisi F4. Department of Medicinal Plant Research and Traditional Medicine, National Institute for.

  18. SPM: Scanning positron microscope

    Directory of Open Access Journals (Sweden)

    Marcel Dickmann

    2015-08-01

    Full Text Available The Munich scanning positron microscope, operated by the Universität der Bundeswehr München and the Technische Universität München, located at NEPOMUC, permits positron lifetime measurements with a lateral resolution in the µm range and within an energy range of 1 – 20 keV.

  19. Microscope on Mars

    Science.gov (United States)

    2004-01-01

    This image taken at Meridiani Planum, Mars by the panoramic camera on the Mars Exploration Rover Opportunity shows the rover's microscopic imager (circular device in center), located on its instrument deployment device, or 'arm.' The image was acquired on the ninth martian day or sol of the rover's mission.

  20. Making Art with Microscopes

    Science.gov (United States)

    Benedis-Grab, Gregory

    2011-01-01

    Interdisciplinary teaching is a great way to focus on overarching concepts and help students make connections across disciplines. Historically, art and science have been connected disciplines. The botanical prints of the 18th and 19th centuries and early work with microscopes are two examples of a need for strong artistic skills in the science…

  1. Terahertz scanning probe microscope

    NARCIS (Netherlands)

    Klapwijk, T.M.

    2014-01-01

    The invention provides aterahertz scanning probe microscope setup comprising (i) a terahertz radiation source configured to generate terahertz radiation; (ii) a terahertz lens configured to receive at least part of the terahertz radiation from the terahertz radiation source; (iii) a cantilever unit

  2. Development of an ultrasound microscope combined with optical microscope for multiparametric characterization of a single cell.

    Science.gov (United States)

    Arakawa, Mototaka; Shikama, Joe; Yoshida, Koki; Nagaoka, Ryo; Kobayashi, Kazuto; Saijo, Yoshifumi

    2015-09-01

    Biomechanics of the cell has been gathering much attention because it affects the pathological status in atherosclerosis and cancer. In the present study, an ultrasound microscope system combined with optical microscope for characterization of a single cell with multiple ultrasound parameters was developed. The central frequency of the transducer was 375 MHz and the scan area was 80 × 80 μm with up to 200 × 200 sampling points. An inverted optical microscope was incorporated in the design of the system, allowing for simultaneous optical observations of cultured cells. Two-dimensional mapping of multiple ultrasound parameters, such as sound speed, attenuation, and acoustic impedance, as well as the thickness, density, and bulk modulus of specimen/cell under investigation, etc., was realized by the system. Sound speed and thickness of a 3T3-L1 fibroblast cell were successfully obtained by the system. The ultrasound microscope system combined with optical microscope further enhances our understanding of cellular biomechanics.

  3. Microscopic dynamical Casimir effect

    Science.gov (United States)

    Souza, Reinaldo de Melo e.; Impens, François; Neto, Paulo A. Maia

    2018-03-01

    We consider an atom in its ground state undergoing a nonrelativistic oscillation in free space. The interaction with the electromagnetic quantum vacuum leads to two effects to leading order in perturbation theory. When the mechanical frequency is larger than the atomic transition frequency, the dominant effect is the motion-induced transition to an excited state with the emission of a photon carrying the excess energy. We compute the angular distribution of emitted photons and the excitation rate. On the other hand, when the mechanical frequency is smaller than the transition frequency, the leading-order effect is the parametric emission of photon pairs, which constitutes the microscopic counterpart of the dynamical Casimir effect. We discuss the properties of the microscopic dynamical Casimir effect and build a connection with the photon production by an oscillating macroscopic metallic mirror.

  4. Ion photon emission microscope

    Science.gov (United States)

    Doyle, Barney L.

    2003-04-22

    An ion beam analysis system that creates microscopic multidimensional image maps of the effects of high energy ions from an unfocussed source upon a sample by correlating the exact entry point of an ion into a sample by projection imaging of the ion-induced photons emitted at that point with a signal from a detector that measures the interaction of that ion within the sample. The emitted photons are collected in the lens system of a conventional optical microscope, and projected on the image plane of a high resolution single photon position sensitive detector. Position signals from this photon detector are then correlated in time with electrical effects, including the malfunction of digital circuits, detected within the sample that were caused by the individual ion that created these photons initially.

  5. Neuromorphic Data Microscope

    Energy Technology Data Exchange (ETDEWEB)

    Naegle, John H.; Suppona, Roger A.; Aimone, James Bradley; James, Conrad D.; Follett, David R.; Townsend, Duncan C.M.; Follett, Pamela L.; Karpman, Gabe D.

    2017-08-01

    In 2016, Lewis Rhodes Labs, (LRL), shipped the first commercially viable Neuromorphic Processing Unit, (NPU), branded as a Neuromorphic Data Microscope (NDM). This product leverages architectural mechanisms derived from the sensory cortex of the human brain to efficiently implement pattern matching. LRL and Sandia National Labs have optimized this product for streaming analytics, and demonstrated a 1,000x power per operation reduction in an FPGA format. When reduced to an ASIC, the efficiency will improve to 1,000,000x. Additionally, the neuromorphic nature of the device gives it powerful computational attributes that are counterintuitive to those schooled in traditional von Neumann architectures. The Neuromorphic Data Microscope is the first of a broad class of brain-inspired, time domain processors that will profoundly alter the functionality and economics of data processing.

  6. Color Laser Microscope

    Science.gov (United States)

    Awamura, D.; Ode, T.; Yonezawa, M.

    1987-04-01

    A color laser microscope utilizing a new color laser imaging system has been developed for the visual inspection of semiconductors. The light source, produced by three lasers (Red; He-Ne, Green; Ar, Blue; He-Cd), is deflected horizontally by an AOD (Acoustic Optical Deflector) and vertically by a vibration mirror. The laser beam is focused in a small spot which is scanned over the sample at high speed. The light reflected back from the sample is reformed to contain linear information by returning to the original vibration mirror. The linear light is guided to the CCD image sensor where it is converted into a video signal. Individual CCD image sensors are used for each of the three R, G, or B color image signals. The confocal optical system with its laser light source yields a color TV monitor image with no flaring and a much sharper resolution than that of the conventional optical microscope. The AOD makes possible a high speed laser scan and a NTSC or PAL TV video signal is produced in real time without any video memory. Since the light source is composed of R, G, and B laser beams, color separation superior to that of white light illumination is achieved. Because of the photometric linearity of the image detector, the R, G, and B outputs of the system are most suitably used for hue analysis. The CCD linear image sensors in the optical system produce no geometrical distortion, and good color registration is available principally. The output signal can be used for high accuracy line width measuring. The many features of the color laser microscope make it ideally suited for the visual inspection of semiconductor processing. A number of these systems have already been installed in such a capacity. The Color Laser Microscope can also be a very useful tool for the fields of material engineering and biotechnology.

  7. Virtual pinhole confocal microscope

    Energy Technology Data Exchange (ETDEWEB)

    George, J.S.; Rector, D.M.; Ranken, D.M. [Los Alamos National Lab., NM (United States). Biophysics Group; Peterson, B. [SciLearn Inc. (United States); Kesteron, J. [VayTech Inc. (United States)

    1999-06-01

    Scanned confocal microscopes enhance imaging capabilities, providing improved contrast and image resolution in 3-D, but existing systems have significant technical shortcomings and are expensive. Researchers at Los Alamos National Laboratory have developed a novel approach--virtual pinhole confocal microscopy--that uses state of the art illumination, detection, and data processing technologies to produce an imager with a number of advantages: reduced cost, faster imaging, improved efficiency and sensitivity, improved reliability and much greater flexibility. Work at Los Alamos demonstrated proof of principle; prototype hardware and software have been used to demonstrate technical feasibility of several implementation strategies. The system uses high performance illumination, patterned in time and space. The authors have built functional confocal imagers using video display technologies (LCD or DLP) and novel scanner based on a micro-lens array. They have developed a prototype system for high performance data acquisition and processing, designed to support realtime confocal imaging. They have developed algorithms to reconstruct confocal images from a time series of spatially sub-sampled images; software development remains an area of active development. These advances allow the collection of high quality confocal images (in fluorescence, reflectance and transmission modes) with equipment that can inexpensively retrofit to existing microscopes. Planned future extensions to these technologies will significantly enhance capabilities for microscopic imaging in a variety of applications, including confocal endoscopy, and confocal spectral imaging.

  8. Thermal Lens Microscope

    Science.gov (United States)

    Uchiyama, Kenji; Hibara, Akihide; Kimura, Hiroko; Sawada, Tsuguo; Kitamori, Takehiko

    2000-09-01

    We developed a novel laser microscope based on the thermal lens effect induced by a coaxial beam comprised of excitation and probe beams. The signal generation mechanism was confirmed to be an authentic thermal lens effect from the measurement of signal and phase dependences on optical configurations between the sample and the probe beam focus, and therefore, the thermal lens effect theory could be applied. Two-point spatial resolution was determined by the spot size of the excitation beam, not by the thermal diffusion length. Sensitivity was quite high, and the detection ability, evaluated using a submicron microparticle containing dye molecules, was 0.8 zmol/μm2, hence a distribution image of trace chemical species could be obtained quantitatively. In addition, analytes are not restricted to fluorescent species, therefore, the thermal lens microscope is a promising analytical microscope. A two-dimensional image of a histamine molecule distribution, which was produced in mast cells at the femtomole level in a human nasal mucous polyp, was obtained.

  9. Q: How do Microscopes Work?

    Science.gov (United States)

    Zimov, Sarah

    2004-01-01

    Microscopes allow scientists to examine everyday objects in extraordinary ways. They provide high-resolution images that show objects in fine detail. This brief article describes the many types of microscopes and how they are used in different scientific venues.

  10. Neutron microscope with refractive wedge

    International Nuclear Information System (INIS)

    Masalovich, S.V.

    1990-01-01

    A possibility of applying a refractive element in a mirror-neutron microscope using ultracold neutrons to reduce neutron aberrations is considered. Application of a refractive element in a neutron microscope with horizontal optical axis is studied. A scheme of neutron microscope with a refractive wedge is presented, evaluation of quartz wedge parameters is made. It is stressed that application of refractive elements in neutron microscopes facilitates aberration reduction in neutron-optical systems

  11. Atomic Force Microscope

    Energy Technology Data Exchange (ETDEWEB)

    Day, R.D.; Russell, P.E.

    1988-12-01

    The Atomic Force Microscope (AFM) is a recently developed instrument that has achieved atomic resolution imaging of both conducting and non- conducting surfaces. Because the AFM is in the early stages of development, and because of the difficulty of building the instrument, it is currently in use in fewer than ten laboratories worldwide. It promises to be a valuable tool for obtaining information about engineering surfaces and aiding the .study of precision fabrication processes. This paper gives an overview of AFM technology and presents plans to build an instrument designed to look at engineering surfaces.

  12. Solid state optical microscope

    Science.gov (United States)

    Young, Ian T.

    1983-01-01

    A solid state optical microscope wherein wide-field and high-resolution images of an object are produced at a rapid rate by utilizing conventional optics with a charge-coupled photodiode array. A galvanometer scanning mirror, for scanning in one of two orthogonal directions is provided, while the charge-coupled photodiode array scans in the other orthogonal direction. Illumination light from the object is incident upon the photodiodes, creating packets of electrons (signals) which are representative of the illuminated object. The signals are then processed, stored in a memory, and finally displayed as a video signal.

  13. Photography with a Microscope

    Science.gov (United States)

    Rost, Fred; Oldfield, Ron

    2000-03-01

    This beautifully illustrated book describes the methods used to record images viewed through a microscope. The text describes the principles and practices of photomicrography, and is written for all who take photomicrographs, beginners and/or experienced practitioners. The authors describe techniques that may be applied to many disciplines for teaching, research, archives, or pleasure. The book includes chapters on standard photography, modern digital techniques, methods for improving contrast, and a short chapter on drawing. In addition to its value as a work of reference, the authors' clear, didactic style makes this book suitable as a textbook for courses in photomicrography and/or elementary light microscopy.

  14. Electron microscope phase enhancement

    Science.gov (United States)

    Jin, Jian; Glaeser, Robert M.

    2010-06-15

    A microfabricated electron phase shift element is used for modifying the phase characteristics of an electron beam passing though its center aperture, while not affecting the more divergent portion of an incident beam to selectively provide a ninety-degree phase shift to the unscattered beam in the back focal plan of the objective lens, in order to realize Zernike-type, in-focus phase contrast in an electron microscope. One application of the element is to increase the contrast of an electron microscope for viewing weakly scattering samples while in focus. Typical weakly scattering samples include biological samples such as macromolecules, or perhaps cells. Preliminary experimental images demonstrate that these devices do apply a ninety degree phase shift as expected. Electrostatic calculations have been used to determine that fringing fields in the region of the scattered electron beams will cause a negligible phase shift as long as the ratio of electrode length to the transverse feature-size aperture is about 5:1. Calculations are underway to determine the feasibility of aspect smaller aspect ratios of about 3:1 and about 2:1.

  15. Designs for a quantum electron microscope.

    Science.gov (United States)

    Kruit, P; Hobbs, R G; Kim, C-S; Yang, Y; Manfrinato, V R; Hammer, J; Thomas, S; Weber, P; Klopfer, B; Kohstall, C; Juffmann, T; Kasevich, M A; Hommelhoff, P; Berggren, K K

    2016-05-01

    One of the astounding consequences of quantum mechanics is that it allows the detection of a target using an incident probe, with only a low probability of interaction of the probe and the target. This 'quantum weirdness' could be applied in the field of electron microscopy to generate images of beam-sensitive specimens with substantially reduced damage to the specimen. A reduction of beam-induced damage to specimens is especially of great importance if it can enable imaging of biological specimens with atomic resolution. Following a recent suggestion that interaction-free measurements are possible with electrons, we now analyze the difficulties of actually building an atomic resolution interaction-free electron microscope, or "quantum electron microscope". A quantum electron microscope would require a number of unique components not found in conventional transmission electron microscopes. These components include a coherent electron beam-splitter or two-state-coupler, and a resonator structure to allow each electron to interrogate the specimen multiple times, thus supporting high success probabilities for interaction-free detection of the specimen. Different system designs are presented here, which are based on four different choices of two-state-couplers: a thin crystal, a grating mirror, a standing light wave and an electro-dynamical pseudopotential. Challenges for the detailed electron optical design are identified as future directions for development. While it is concluded that it should be possible to build an atomic resolution quantum electron microscope, we have also identified a number of hurdles to the development of such a microscope and further theoretical investigations that will be required to enable a complete interpretation of the images produced by such a microscope. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  16. A two-dimensional Dirac fermion microscope

    DEFF Research Database (Denmark)

    Bøggild, Peter; Caridad, Jose; Stampfer, Christoph

    2017-01-01

    D electron guns, deflectors, tunable lenses and various detectors. The simulations show how simple objects can be imaged with well-controlled and collimated in-plane beams consisting of relativistic charge carriers. Finally, we discuss the potential of such microscopes for investigating edges...

  17. Anisotropic contrast optical microscope.

    Science.gov (United States)

    Peev, D; Hofmann, T; Kananizadeh, N; Beeram, S; Rodriguez, E; Wimer, S; Rodenhausen, K B; Herzinger, C M; Kasputis, T; Pfaunmiller, E; Nguyen, A; Korlacki, R; Pannier, A; Li, Y; Schubert, E; Hage, D; Schubert, M

    2016-11-01

    An optical microscope is described that reveals contrast in the Mueller matrix images of a thin, transparent, or semi-transparent specimen located within an anisotropic object plane (anisotropic filter). The specimen changes the anisotropy of the filter and thereby produces contrast within the Mueller matrix images. Here we use an anisotropic filter composed of a semi-transparent, nanostructured thin film with sub-wavelength thickness placed within the object plane. The sample is illuminated as in common optical microscopy but the light is modulated in its polarization using combinations of linear polarizers and phase plate (compensator) to control and analyze the state of polarization. Direct generalized ellipsometry data analysis approaches permit extraction of fundamental Mueller matrix object plane images dispensing with the need of Fourier expansion methods. Generalized ellipsometry model approaches are used for quantitative image analyses. These images are obtained from sets of multiple images obtained under various polarizer, analyzer, and compensator settings. Up to 16 independent Mueller matrix images can be obtained, while our current setup is limited to 11 images normalized by the unpolarized intensity. We demonstrate the anisotropic contrast optical microscope by measuring lithographically defined micro-patterned anisotropic filters, and we quantify the adsorption of an organic self-assembled monolayer film onto the anisotropic filter. Comparison with an isotropic glass slide demonstrates the image enhancement obtained by our method over microscopy without the use of an anisotropic filter. In our current instrument, we estimate the limit of detection for organic volumetric mass within the object plane of ≈49 fg within ≈7 × 7 μm 2 object surface area. Compared to a quartz crystal microbalance with dissipation instrumentation, where contemporary limits require a total load of ≈500 pg for detection, the instrumentation demonstrated here improves

  18. Microscopic entropy and nonlocality

    International Nuclear Information System (INIS)

    Karpov, E.; Ordonets, G.; Petroskij, T.; Prigozhin, I.

    2003-01-01

    We have obtained a microscopic expression for entropy in terms of H function based on nonunitary Λ transformation which leads from the time evolution as a unitary group to a Markovian dynamics and unifies the reversible and irreversible aspects of quantum mechanics. This requires a new representation outside the Hilbert space. In terms of H, we show the entropy production and the entropy flow during the emission and absorption of radiation by an atom. Analyzing the time inversion experiment, we emphasize the importance of pre- and postcollisional correlations, which break the symmetry between incoming and outgoing waves. We consider the angle dependence of the H function in a three-dimensional situation. A model including virtual transitions is discussed in a subsequent paper

  19. Embryos, microscopes, and society.

    Science.gov (United States)

    Maienschein, Jane

    2016-06-01

    Embryos have different meanings for different people and in different contexts. Seen under the microscope, the biological embryo starts out as one cell and then becomes a bunch of cells. Gradually these divide and differentiate to make up the embryo, which in humans becomes a fetus at eight weeks, and then eventually a baby. At least, that happens in those cases that carry through normally and successfully. Yet a popular public perception imagines the embryo as already a little person in the very earliest stages of development, as if it were predictably to become an adult. In actuality, cells can combine, pull apart, and recombine in a variety of ways and still produce embryos, whereas most embryos never develop into adults at all. Biological embryos and popular imaginations of embryos diverge. This paper looks at some of the historical reasons for and social implications of that divergence. Copyright © 2016 The Author. Published by Elsevier Ltd.. All rights reserved.

  20. Imaging arrangement and microscope

    Science.gov (United States)

    Pertsinidis, Alexandros; Chu, Steven

    2015-12-15

    An embodiment of the present invention is an imaging arrangement that includes imaging optics, a fiducial light source, and a control system. In operation, the imaging optics separate light into first and second tight by wavelength and project the first and second light onto first and second areas within first and second detector regions, respectively. The imaging optics separate fiducial light from the fiducial light source into first and second fiducial light and project the first and second fiducial light onto third and fourth areas within the first and second detector regions, respectively. The control system adjusts alignment of the imaging optics so that the first and second fiducial light projected onto the first and second detector regions maintain relatively constant positions within the first and second detector regions, respectively. Another embodiment of the present invention is a microscope that includes the imaging arrangement.

  1. Microscopic Theory of Transconductivity

    Directory of Open Access Journals (Sweden)

    A. P. Jauho

    1998-01-01

    Full Text Available Measurements of momentum transfer between two closely spaced mesoscopic electronic systems, which couple via Coulomb interaction but where tunneling is inhibited, have proven to be a fruitful method of extracting information about interactions in mesoscopic systems. We report a fully microscopic theory for transconductivity σ12, or, equivalently, momentum transfer rate between the system constituents. Our main formal result expresses the transconductivity in terms of two fluctuation diagrams, which are topologically related, but not equivalent to, the Azlamazov-Larkin and Maki-Thompson diagrams known for superconductivity. In the present paper the magnetic field dependence of σ12 is discussed, and we find that σ12(B is strongly enhanced over its zero field value, and it displays strong features, which can be understood in terms of a competition between density-of-states and screening effects.

  2. Optical modeling of Fresnel zoneplate microscopes.

    Science.gov (United States)

    Naulleau, Patrick P; Mochi, Iacopo; Goldberg, Kenneth A

    2011-07-10

    Defect free masks remain one of the most significant challenges facing the commercialization of extreme ultraviolet (EUV) lithography. Progress on this front requires high-performance wavelength-specific metrology of EUV masks, including high-resolution and aerial-image microscopy performed near the 13.5 nm wavelength. Arguably the most cost-effective and rapid path to proliferating this capability is through the development of Fresnel zoneplate-based microscopes. Given the relative obscurity of such systems, however, modeling tools are not necessarily optimized to deal with them and their imaging properties are poorly understood. Here we present a modeling methodology to analyze zoneplate microscopes based on commercially available optical modeling software and use the technique to investigate the imaging performance of an off-axis EUV microscope design. The modeling predicts that superior performance can be achieved by tilting the zoneplate, making it perpendicular to the chief ray at the center of the field, while designing the zoneplate to explicitly work in that tilted plane. Although the examples presented here are in the realm of EUV mask inspection, the methods described and analysis results are broadly applicable to zoneplate microscopes in general, including full-field soft-x-ray microscopes routinely used in the synchrotron community. © 2011 Optical Society of America

  3. Optical modeling of Fresnel zoneplate microscopes

    International Nuclear Information System (INIS)

    Naulleau, Patrick P.; Mochi, Iacopo; Goldberg, Kenneth A.

    2011-01-01

    Defect free masks remain one of the most significant challenges facing the commercialization of extreme ultraviolet (EUV) lithography. Progress on this front requires high-performance wavelength-specific metrology of EUV masks, including high-resolution and aerial-image microscopy performed near the 13.5 nm wavelength. Arguably the most cost-effective and rapid path to proliferating this capability is through the development of Fresnel zoneplate-based microscopes. Given the relative obscurity of such systems, however, modeling tools are not necessarily optimized to deal with them and their imaging properties are poorly understood. Here we present a modeling methodology to analyze zoneplate microscopes based on commercially available optical modeling software and use the technique to investigate the imaging performance of an off-axis EUV microscope design. The modeling predicts that superior performance can be achieved by tilting the zoneplate, making it perpendicular to the chief ray at the center of the field, while designing the zoneplate to explicitly work in that tilted plane. Although the examples presented here are in the realm of EUV mask inspection, the methods described and analysis results are broadly applicable to zoneplate microscopes in general, including full-field soft-x-ray microscopes routinely used in the synchrotron community.

  4. Microscopic fungi as significant sesquiterpene emission sources

    Science.gov (United States)

    HorváTh, Eszter; Hoffer, AndráS.; SebőK, Flóra; Dobolyi, Csaba; Szoboszlay, SáNdor; Kriszt, BaláZs; GelencséR, AndráS.

    2011-08-01

    Among the volatile organic compounds emitted by vegetation, isoprene, monoterpenes, sesquiterpenes, and their derivatives are thought to contribute to secondary organic aerosol formation. Although it is well known that microscopic fungi globally turn over vast amount of carbon by decomposing the organic matter in the soil, vegetation is considered as the exclusive source of biogenic secondary organic aerosol precursors in various atmospheric models. Secondary fungal metabolites including sesquiterpenes have been recognized as characteristic volatile organic compounds emitted by fungi. In the present study, we investigated the rates of sesquiterpene emission of microscopic fungi to establish their potential significance compared to those from vegetation. To sample the headspace of the pure culture of some common fungi, we used an aseptic flow-through apparatus designed for solid phase microextraction in our laboratory. The identified sesquiterpenes in the headspace extracts were quantified for eight strains of microscopic fungi belonging to four different genera. Our results showed that microscopic fungi emit a considerable amount of sesquiterpenes. Based on our first estimations microscopic fungi may be considered as potentially significant sesquiterpene emission sources whose contribution to secondary organic aerosol formation may be comparable to that of vegetation.

  5. Smartphone Magnification Attachment: Microscope or Magnifying Glass

    Science.gov (United States)

    Hergemöller, Timo; Laumann, Daniel

    2017-09-01

    Today smartphones and tablets do not merely pervade our daily life, but also play a major role in STEM education in general, and in experimental investigations in particular. Enabling teachers and students to make use of these new techniques in physics lessons requires supplying capable and affordable applications. Our article presents the improvement of a low-cost technique turning smartphones into powerful magnifying glasses or microscopes. Adding only a 3D-printed clip attached to the smartphone's camera and inserting a small glass bead in this clip enables smartphones to take pictures with up to 780x magnification (see Fig. 1). In addition, the construction of the smartphone attachments helps to explain and examine the differences between magnifying glasses and microscopes, and shows that the widespread term "smartphone microscope" for this technique is inaccurate from a physics educational perspective.

  6. CHAMP (Camera, Handlens, and Microscope Probe)

    Science.gov (United States)

    Mungas, Greg S.; Boynton, John E.; Balzer, Mark A.; Beegle, Luther; Sobel, Harold R.; Fisher, Ted; Klein, Dan; Deans, Matthew; Lee, Pascal; Sepulveda, Cesar A.

    2005-01-01

    CHAMP (Camera, Handlens And Microscope Probe)is a novel field microscope capable of color imaging with continuously variable spatial resolution from infinity imaging down to diffraction-limited microscopy (3 micron/pixel). As a robotic arm-mounted imager, CHAMP supports stereo imaging with variable baselines, can continuously image targets at an increasing magnification during an arm approach, can provide precision rangefinding estimates to targets, and can accommodate microscopic imaging of rough surfaces through a image filtering process called z-stacking. CHAMP was originally developed through the Mars Instrument Development Program (MIDP) in support of robotic field investigations, but may also find application in new areas such as robotic in-orbit servicing and maintenance operations associated with spacecraft and human operations. We overview CHAMP'S instrument performance and basic design considerations below.

  7. Femtosecond photoelectron point projection microscope

    International Nuclear Information System (INIS)

    Quinonez, Erik; Handali, Jonathan; Barwick, Brett

    2013-01-01

    By utilizing a nanometer ultrafast electron source in a point projection microscope we demonstrate that images of nanoparticles with spatial resolutions of the order of 100 nanometers can be obtained. The duration of the emission process of the photoemitted electrons used to make images is shown to be of the order of 100 fs using an autocorrelation technique. The compact geometry of this photoelectron point projection microscope does not preclude its use as a simple ultrafast electron microscope, and we use simple analytic models to estimate temporal resolutions that can be expected when using it as a pump-probe ultrafast electron microscope. These models show a significant increase in temporal resolution when comparing to ultrafast electron microscopes based on conventional designs. We also model the microscopes spectroscopic abilities to capture ultrafast phenomena such as the photon induced near field effect

  8. Proper alignment of the microscope.

    Science.gov (United States)

    Rottenfusser, Rudi

    2013-01-01

    The light microscope is merely the first element of an imaging system in a research facility. Such a system may include high-speed and/or high-resolution image acquisition capabilities, confocal technologies, and super-resolution methods of various types. Yet more than ever, the proverb "garbage in-garbage out" remains a fact. Image manipulations may be used to conceal a suboptimal microscope setup, but an artifact-free image can only be obtained when the microscope is optimally aligned, both mechanically and optically. Something else is often overlooked in the quest to get the best image out of the microscope: Proper sample preparation! The microscope optics can only do its job when its design criteria are matched to the specimen or vice versa. The specimen itself, the mounting medium, the cover slip, and the type of immersion medium (if applicable) are all part of the total optical makeup. To get the best results out of a microscope, understanding the functions of all of its variable components is important. Only then one knows how to optimize these components for the intended application. Different approaches might be chosen to discuss all of the microscope's components. We decided to follow the light path which starts with the light source and ends at the camera or the eyepieces. To add more transparency to this sequence, the section up to the microscope stage was called the "Illuminating Section", to be followed by the "Imaging Section" which starts with the microscope objective. After understanding the various components, we can start "working with the microscope." To get the best resolution and contrast from the microscope, the practice of "Koehler Illumination" should be understood and followed by every serious microscopist. Step-by-step instructions as well as illustrations of the beam path in an upright and inverted microscope are included in this chapter. A few practical considerations are listed in Section 3. Copyright © 2013 Elsevier Inc. All rights

  9. Scanning Electron Microscope Analysis System

    Data.gov (United States)

    Federal Laboratory Consortium — This facility provides the capability to examine surfaces microscopically with high resolution (5 nanometers), perform micro chemical analyses of these surfaces, and...

  10. Photon scanning tunneling microscope in combination with a force microscope

    NARCIS (Netherlands)

    Moers, M.H.P.; Moers, M.H.P.; Tack, R.G.; van Hulst, N.F.; Bölger, B.; Bölger, B.

    1994-01-01

    The simultaneous operation of a photon scanning tunneling microscope with an atomic force microscope is presented. The use of standard atomic force silicon nitride cantilevers as near-field optical probes offers the possibility to combine the two methods. Vertical forces and torsion are detected

  11. Stage II recovery behavior of a series of ion-irradiated platinum (gold) alloys as studied by field-ion microscopy. [0. 10, 0. 62, and 4. 0 at. percent Au and pure Pt

    Energy Technology Data Exchange (ETDEWEB)

    Wei, C.Y.; Seidman, D.N.

    1976-11-01

    Direct and visible evidence was obtained for long-range migration of self-interstitial atoms (SIAs) in Stage II of three different ion-irradiated platinum (gold) alloys. Field-ion microscope (FIM) specimens of Pt--0.10, 0.62 and 4.0 at. percent Au alloys were irradiated in-situ with 30-keV W/sup +/ or Pt/sup +/ ions at a tip temperature of 35 to 41 K at 2 x 10/sup -9/ torr. Direct observation of the surfaces of the FIM specimens during isochronal warming experiments to 100 K showed that a flux of SIAs crossed the surfaces of the specimens between 40 to 100 K. The spectrum for each alloy consisted of two recovery peaks (substages II/sub B/ and II/sub C/). The results are explained on the basis of an impurity-delayed diffusion mechanism employing a two-level trapping model. The application of this diffusion model to the isochronal recovery spectra yielded a dissociation enthalpy (DELTAh/sub li-Au//sup diss/) and an effective diffusion coefficient for each substage; for substage II/sub B/ DELTAh/sub li-Au//sup diss/ (II/sub B/) = 0.15 eV and for substage II/sub C/ DELTAh/sub li-Au//sup diss/ (II/sub C/) = 0.24 eV. A series of detailed control experiments was also performed to show that the imaging electric field had not caused the observed long-range migration of SIAs and that the observed effects were not the result of surface artifacts. 14 figures, 6 tables.

  12. The Latest in Handheld Microscopes

    Science.gov (United States)

    Wighting, Mervyn J.; Lucking, Robert A.; Christmann, Edwin P.

    2004-01-01

    Around 1590, Zacharias Jansenn of Holland invented the microscope. Jansenn, an eyeglass maker by trade, experimented with lenses and discovered that things appeared closer with combinations of lenses. Over the past 400 years, several refinements to microscopes have occurred, making it possible to magnify objects between 200 and 1,500 times their…

  13. Midfield microscope : Exploring the extraordinary

    NARCIS (Netherlands)

    Docter, M.W.

    2008-01-01

    In this thesis the development of the midfield microscope is presented. This is a microscope in which the extraordinary transmission (EOT) through sub-wavelength hole-arrays is applied. Before trying to combine microscopy and EOT, we look at them separately. In chapter 1 an overview is given of the

  14. The head-mounted microscope.

    Science.gov (United States)

    Chen, Ting; Dailey, Seth H; Naze, Sawyer A; Jiang, Jack J

    2012-04-01

    Microsurgical equipment has greatly advanced since the inception of the microscope into the operating room. These advancements have allowed for superior surgical precision and better post-operative results. This study focuses on the use of the Leica HM500 head-mounted microscope for the operating phonosurgeon. The head-mounted microscope has an optical zoom from 2× to 9× and provides a working distance from 300 mm to 700 mm. The headpiece, with its articulated eyepieces, adjusts easily to head shape and circumference, and offers a focus function, which is either automatic or manually controlled. We performed five microlaryngoscopic operations utilizing the head-mounted microscope with successful results. By creating a more ergonomically favorable operating posture, a surgeon may be able to obtain greater precision and success in phonomicrosurgery. Phonomicrosurgery requires the precise manipulation of long-handled cantilevered instruments through the narrow bore of a laryngoscope. The head-mounted microscope shortens the working distance compared with a stand microscope, thereby increasing arm stability, which may improve surgical precision. Also, the head-mounted design permits flexibility in head position, enabling operator comfort, and delaying musculoskeletal fatigue. A head-mounted microscope decreases the working distance and provides better ergonomics in laryngoscopic microsurgery. These advances provide the potential to promote precision in phonomicrosurgery. Copyright © 2011 The American Laryngological, Rhinological, and Otological Society, Inc.

  15. Mobile microscope complex GIB-1

    International Nuclear Information System (INIS)

    Belyakov, A.V.; Gorbachev, A.N.

    2002-01-01

    To study microstructure in operating pipelines of power units a mobile microscope system is developed and successfully used. The system includes a portable microscope, a monitor, power supply and a portable computer. The monitor is used for surveying images from a video camera mounted on the microscope. The magnification on visual examination constitutes x 100 and x 500. Diameters of pipelines examined should not be less than 130 mm. Surface preparation for microstructural studies includes routine mechanical rough grinding and polishing with subsequent etching [ru

  16. A microscope for Fermi gases

    International Nuclear Information System (INIS)

    Omran, Ahmed

    2016-01-01

    This thesis reports on a novel quantum gas microscope to investigate many-body systems of fermionic atoms in optical lattices. Single-site resolved imaging of ultracold lattice gases has enabled powerful studies of bosonic quantum many-body systems. The extension of this capability to Fermi gases offers new prospects to studying complex phenomena of strongly correlated systems, for which numerical simulations are often out of reach. Using standard techniques of laser cooling, optical trapping, and evaporative cooling, ultracold Fermi gases of 6 Li are prepared and loaded into a large-scale 2D optical lattice of flexible geometry. The atomic distribution is frozen using a second, short-scaled lattice, where we perform Raman sideband cooling to induce fluorescence on each atom while maintaining its position. Together with high-resolution imaging, the fluorescence signals allow for reconstructing the initial atom distribution with single-site sensitivity and high fidelity. Magnetically driven evaporative cooling in the plane allows for producing degenerate Fermi gases with almost unity filling in the initial lattice, allowing for the first microscopic studies of ultracold gases with clear signatures of Fermi statistics. By preparing an ensemble of spin-polarised Fermi gases, we detect a flattening of the density profile towards the centre of the cloud, which is a characteristic of a band-insulating state. In one set of experiments, we demonstrate that losses of atom pairs on a single lattice site due to light-assisted collisions are circumvented. The oversampling of the second lattice allows for deterministic separation of the atom pairs into different sites. Compressing a high-density sample in a trap before loading into the lattice leads to many double occupancies of atoms populating different bands, which we can image with no evidence for pairwise losses. We therefore gain direct access to the true number statistics on each lattice site. Using this feature, we can

  17. Center of excellence: Microlaser microscope

    Science.gov (United States)

    Webb, R. H.

    This Center-of-Excellence grant has two components: development of an imaging system based on microlaser arrays forms a central project among a group of laser diagnostic and therapeutic efforts primarily funded outside the grant. In these first 8 months we have set up the Microlaser Microscope using small microlaser arrays. We have emphasized the basics of microlaser handling and electronic addressing and the optics of the microscope. Details of electronics and optics given here will be used in the larger arrays which should be available soon. After a description of the central Microlaser Microscope project, we touch briefly on the other projects of the Center, which have been outstandingly fruitful this year. Publications are necessarily concerned with the smaller projects, since the Microlaser Microscope is in its early stages.

  18. A high resolution ion microscope for cold atoms

    International Nuclear Information System (INIS)

    Stecker, Markus; Schefzyk, Hannah; Fortágh, József; Günther, Andreas

    2017-01-01

    We report on an ion-optical system that serves as a microscope for ultracold ground state and Rydberg atoms. The system is designed to achieve a magnification of up to 1000 and a spatial resolution in the 100 nm range, thereby surpassing many standard imaging techniques for cold atoms. The microscope consists of four electrostatic lenses and a microchannel plate in conjunction with a delay line detector in order to achieve single particle sensitivity with high temporal and spatial resolution. We describe the design process of the microscope including ion-optical simulations of the imaging system and characterize aberrations and the resolution limit. Furthermore, we present the experimental realization of the microscope in a cold atom setup and investigate its performance by patterned ionization with a structure size down to 2.7 μ m. The microscope meets the requirements for studying various many-body effects, ranging from correlations in cold quantum gases up to Rydberg molecule formation. (paper)

  19. On thermodynamic and microscopic reversibility

    International Nuclear Information System (INIS)

    Crooks, Gavin E

    2011-01-01

    The word 'reversible' has two (apparently) distinct applications in statistical thermodynamics. A thermodynamically reversible process indicates an experimental protocol for which the entropy change is zero, whereas the principle of microscopic reversibility asserts that the probability of any trajectory of a system through phase space equals that of the time reversed trajectory. However, these two terms are actually synonymous: a thermodynamically reversible process is microscopically reversible, and vice versa

  20. Scanning Miniature Microscopes without Lenses

    Science.gov (United States)

    Wang, Yu

    2009-01-01

    The figure schematically depicts some alternative designs of proposed compact, lightweight optoelectronic microscopes that would contain no lenses and would generate magnified video images of specimens. Microscopes of this type were described previously in Miniature Microscope Without Lenses (NPO - 20218), NASA Tech Briefs, Vol. 22, No. 8 (August 1998), page 43 and Reflective Variants of Miniature Microscope Without Lenses (NPO 20610), NASA Tech Briefs, Vol. 26, No. 9 (September 1999), page 6a. To recapitulate: In the design and construction of a microscope of this type, the focusing optics of a conventional microscope are replaced by a combination of a microchannel filter and a charge-coupled-device (CCD) image detector. Elimination of focusing optics reduces the size and weight of the instrument and eliminates the need for the time-consuming focusing operation. The microscopes described in the cited prior articles contained two-dimensional CCDs registered with two-dimensional arrays of microchannels and, as such, were designed to produce full two-dimensional images, without need for scanning. The microscopes of the present proposal would contain one-dimensional (line image) CCDs registered with linear arrays of microchannels. In the operation of such a microscope, one would scan a specimen along a line perpendicular to the array axis (in other words, one would scan in pushbroom fashion). One could then synthesize a full two-dimensional image of the specimen from the line-image data acquired at one-pixel increments of position along the scan. In one of the proposed microscopes, a beam of unpolarized light for illuminating the specimen would enter from the side. This light would be reflected down onto the specimen by a nonpolarizing beam splitter attached to the microchannels at their lower ends. A portion of the light incident on the specimen would be reflected upward, through the beam splitter and along the microchannels, to form an image on the CCD. If the

  1. Axiomatic electrodynamics and microscopic mechanics

    International Nuclear Information System (INIS)

    Yussouff, M.

    1981-04-01

    A new approach to theoretical physics, along with the basic formulation of a new MICROSCOPIC MECHANICS for the motion of small charged particles is described in this set of lecture notes. Starting with the classical (Newtonian) mechanics and classical fields, the important but well known properties of Classical Electromagnetic field are discussed up to section 4. The next nection describes the usual radiation damping theory and its difficulties. It is argued that the usual treatment of radiation damping is not valid for small space and time intervals and the true description of motion requires a new type of mechanics - the MICROSCOPIC MECHANICS: Section 6 and 7 are devoted to showing that not only the new microscopic mechanics goes over to Newtonian mechanics in the proper limit, but also it is closely connected with Quantum Mechanics. All the known results of the Schroedinger theory can be reproduced by microscopic mechanics which also gives a clear physical picture. It removes Einstein's famous objections against Quantum Theory and provides a clear distinction between classical and Quantum behavior. Seven Axioms (three on Classical Mechanics, two for Maxwell's theory, one for Relativity and a new Axiom on Radiation damping) are shown to combine Classical Mechanics, Maxwellian Electrodynamics, Relativity and Schroedinger's Quantum Theory within a single theoretical framework under Microscopic Mechanics which awaits further development at the present time. (orig.)

  2. Designs for a quantum electron microscope

    International Nuclear Information System (INIS)

    Kruit, P.; Hobbs, R.G.; Kim, C-S.; Yang, Y.; Manfrinato, V.R.; Hammer, J.; Thomas, S.; Weber, P.; Klopfer, B.; Kohstall, C.; Juffmann, T.; Kasevich, M.A.; Hommelhoff, P.; Berggren, K.K.

    2016-01-01

    One of the astounding consequences of quantum mechanics is that it allows the detection of a target using an incident probe, with only a low probability of interaction of the probe and the target. This ‘quantum weirdness’ could be applied in the field of electron microscopy to generate images of beam-sensitive specimens with substantially reduced damage to the specimen. A reduction of beam-induced damage to specimens is especially of great importance if it can enable imaging of biological specimens with atomic resolution. Following a recent suggestion that interaction-free measurements are possible with electrons, we now analyze the difficulties of actually building an atomic resolution interaction-free electron microscope, or “quantum electron microscope”. A quantum electron microscope would require a number of unique components not found in conventional transmission electron microscopes. These components include a coherent electron beam-splitter or two-state-coupler, and a resonator structure to allow each electron to interrogate the specimen multiple times, thus supporting high success probabilities for interaction-free detection of the specimen. Different system designs are presented here, which are based on four different choices of two-state-couplers: a thin crystal, a grating mirror, a standing light wave and an electro-dynamical pseudopotential. Challenges for the detailed electron optical design are identified as future directions for development. While it is concluded that it should be possible to build an atomic resolution quantum electron microscope, we have also identified a number of hurdles to the development of such a microscope and further theoretical investigations that will be required to enable a complete interpretation of the images produced by such a microscope. - Highlights: • Quantum electron microscopy has the potential of reducing radiation damage. • QEM requires a fraction of the electron wave to pass through the sample

  3. Microscope and method of use

    Science.gov (United States)

    Bongianni, Wayne L.

    1984-01-01

    A method and apparatus for electronically focusing and electronically scanning microscopic specimens are given. In the invention, visual images of even moving, living, opaque specimens can be acoustically obtained and viewed with virtually no time needed for processing (i.e., real time processing is used). And planar samples are not required. The specimens (if planar) need not be moved during scanning, although it will be desirable and possible to move or rotate nonplanar specimens (e.g., laser fusion targets) against the lens of the apparatus. No coupling fluid is needed, so specimens need not be wetted. A phase acoustic microscope is also made from the basic microscope components together with electronic mixers.

  4. Electron microscope studies

    International Nuclear Information System (INIS)

    Crewe, A.V.; Kapp, O.H.

    1990-01-01

    Our laboratory has made significant progress this year in devising improved electron-optical systems, in studying invertebrate hemoglobins with the STEM, and in achieving a workable sub-angstrom STEM. Our goal in electron optics is to improve resolution by producing spherical and chromatic aberration coefficients with signs opposite those of magnetic lenses. We have progressed toward this goal through calculations that explore the addition of electrodes to electron mirrors to reduce these two geometric aberrations and by devising a beam separation system that won't introduce asymmetrical aberrations. Some promising new designs of magnetic lenses for SEM applications have also been investigated. We have continued our exploration of the quaternary structure of the invertebrate hemoglobins and are now among the top laboratories in this area of expertise. In addition, we have overcome many of our electronic difficulties on the sub-angstrom STEM and have made significant progress toward achieving an operational system. The addition of an IBM RISC-6000 workstation to our lab has significantly increased our image processing capabilities

  5. Atomic force microscope featuring an integrated optical microscope

    NARCIS (Netherlands)

    Putman, C.A.J.; Putman, Constant A.J.; de Grooth, B.G.; van Hulst, N.F.; Greve, Jan

    1992-01-01

    The atomic force microscope (AFM) is used to image the surface of both conductors and nonconductors. Biological specimens constitute a large group of nonconductors. A disadvantage of most AFM's is the fact that relatively large areas of the sample surface have to be scanned to pinpoint a biological

  6. Spectroscopy of electron irradiated polymers in electron microscope

    International Nuclear Information System (INIS)

    Faraj, S.H.; Salih, S.M.

    1981-01-01

    The damage induced by energetic electrons in the course of irradiation of polymers in a transmission electron microscope was investigated spectroscopically. Damage on the molecular level has been detected at very low exposure doses. These effects have been induced by electron doses less than that received by the specimen when it is situated at its usual place of the specimen stage in the electron microscope by a factor of 1,000. (author)

  7. Microscopic optical potential at medium energies

    International Nuclear Information System (INIS)

    Malecki, A.

    1979-01-01

    The problems concerning a microscopic optical model for the elastic nuclear collisions at medium energies are discussed. We describe the method for constructing the optical potential which makes use of the particular properties of quantum scattering in the eikonal limit. The resulting potential is expressed in terms of the nuclear wave functions and the nucleon-nucleon scattering amplitudes. This potential has a dynamic character since by including the effects of multiple scattering it allows for the possibility of intermediate excitations of the projectile and target nuclei. The use of the potential in the exact wave equation accounts for the most important mechanisms present in the collisions between composite particles. The microscopic optical model was successfully applied in the analysis of elastic scattering of protons and α-particles on atomic nuclei in the energy range of 300-1000 MeV/nucleon. The dynamic optical potential in this case represents a considerable improvement over the eikonal Glauber model and the static optical potential of Watson. The possibilities to extend the microscopic description of the proton-nucleus interaction by considering the spin dependence of the elementary amplitude and the Majorana exchange effects were investigated. (author)

  8. Image inpainting for the differential confocal microscope

    Science.gov (United States)

    Qiu, Lirong; Wang, Lei; Liu, Dali; Hou, Maosheng; Zhao, Weiqian

    2015-02-01

    In the process of zero-crossing trigger measurement of differential confocal microscope, the sample surface features or tilt will cause the edges can't be triggered. Meanwhile, environment vibration can also cause false triggering. In order to restore the invalid information of sample, and realize high-precision surface topography measurement, Total Variation (TV) inpainting model is applied to restore the scanning images. Emulation analysis and experimental verification of this method are investigated. The image inpainting algorithm based on TV model solves the minimization of the energy equation by calculus of variations, and it can effectively restore the non-textured image with noises. Using this algorithm, the simulation confocal laser intensity curve and height curve of standard step sample are restored. After inpainting the intensity curve below the threshold is repaired, the maximum deviation from ideal situation is 0.0042, the corresponding edge contour of height curve is restored, the maximum deviation is 0.1920, which proves the algorithm is effective. Experiment of grating inpainting indicates that the TV algorithm can restore the lost information caused by failed triggering and eliminate the noise caused by false triggering in zero-crossing trigger measurement of differential confocal microscope. The restored image is consistent with the scanning result of OLYMPUS confocal microscope, which can satisfy the request of follow-up measurement analysis.

  9. Infrared up-conversion microscope

    DEFF Research Database (Denmark)

    2014-01-01

    There is presented an up-conversion infrared microscope (110) arranged for imaging an associated object (130), wherein the up-conversion infrared microscope (110) comprises a non-linear crystal (120) arranged for up-conversion of infrared electromagnetic radiation, and wherein an objective optical...... component (100) has an entrance pupil with a first diameter D1, and an optical component system which is arranged for forming an external image (136) of the back-focal plane (132) of the objective optical component (100), which has a diameter (given by the diameter of a circle enclosing all optical paths...

  10. Research on improving performance to metallographic microscopes

    Directory of Open Access Journals (Sweden)

    Teodor Socaciu

    2011-12-01

    Full Text Available Precision optical components from an old optical microscope can be improved and emphasized with a dedicated digital microscope camera. This is an affordable way to obtain a high performance metallographic or biological microscope, with minimum of spending. This paper study those ways and adapts a camera to existing microscopes for researchers use, Optimizing visualization by projecting the image and improving the microscope use by different options of capture and image processing.

  11. Curriculum Guidelines for Microscopic Anatomy.

    Science.gov (United States)

    Journal of Dental Education, 1993

    1993-01-01

    The American Association of Dental Schools' guidelines for curricula in microscopic anatomy offer an overview of the histology curriculum, note primary educational goals, outline specific content for general and oral histology, suggest prerequisites, and make recommendations for sequencing. Appropriate faculty and facilities are also suggested.…

  12. Microscopic cross sections: An utopia?

    Energy Technology Data Exchange (ETDEWEB)

    Hilaire, S. [CEA Bruyeres-le-Chatel, DIF 91 (France); Koning, A.J. [Nuclear Research and Consultancy Group, PO Box 25, 1755 ZG Petten (Netherlands); Goriely, S. [Institut d' Astronomie et d' Astrophysique, Universite Libre de Bruxelles, Campus de la Plaine, CP 226, 1050 Brussels (Belgium)

    2010-07-01

    The increasing need for cross sections far from the valley of stability poses a challenge for nuclear reaction models. So far, predictions of cross sections have relied on more or less phenomenological approaches, depending on parameters adjusted to available experimental data or deduced from systematical relations. While such predictions are expected to be reliable for nuclei not too far from the experimentally known regions, it is clearly preferable to use more fundamental approaches, based on sound physical bases, when dealing with very exotic nuclei. Thanks to the high computer power available today, all major ingredients required to model a nuclear reaction can now be (and have been) microscopically (or semi-microscopically) determined starting from the information provided by a nucleon-nucleon effective interaction. We have implemented all these microscopic ingredients in the TALYS nuclear reaction code, and we are now almost able to perform fully microscopic cross section calculations. The quality of these ingredients and the impact of using them instead of the usually adopted phenomenological parameters will be discussed. (authors)

  13. Microscopic cross sections: An utopia?

    International Nuclear Information System (INIS)

    Hilaire, S.; Koning, A.J.; Goriely, S.

    2010-01-01

    The increasing need for cross sections far from the valley of stability poses a challenge for nuclear reaction models. So far, predictions of cross sections have relied on more or less phenomenological approaches, depending on parameters adjusted to available experimental data or deduced from systematical relations.While such predictions are expected to be reliable for nuclei not too far from the experimentally known regions, it is clearly preferable to use more fundamental approaches, based on sound physical bases, when dealing with very exotic nuclei. Thanks to the high computer power available today, all major ingredients required to model a nuclear reaction can now be (and have been) microscopically (or semi-microscopically) determined starting from the information provided by a nucleon-nucleon effective interaction. We have implemented all these microscopic ingredients in the TALYS nuclear reaction code, and we are now almost able to perform fully microscopic cross section calculations. The quality of these ingredients and the impact of using them instead of the usually adopted phenomenological parameters will be discussed. (authors)

  14. Microscope sterility during spine surgery.

    Science.gov (United States)

    Bible, Jesse E; O'Neill, Kevin R; Crosby, Colin G; Schoenecker, Jonathan G; McGirt, Matthew J; Devin, Clinton J

    2012-04-01

    Prospective study. Assess the contamination rates of sterile microscope drapes after spine surgery. The use of the operating microscope has become more prevalent in certain spine procedures, providing superior magnification, visualization, and illumination of the operative field. However, it may represent an additional source of bacterial contamination and increase the risk of developing a postoperative infection. This study included 25 surgical spine cases performed by a single spine surgeon that required the use of the operative microscope. Sterile culture swabs were used to obtain samples from 7 defined locations on the microscope drape after its use during the operation. The undraped technician's console was sampled in each case as a positive control, and an additional 25 microscope drapes were swabbed immediately after they were applied to the microscope to obtain negative controls. Swab samples were assessed for bacterial growth on 5% sheep blood Columbia agar plates using a semiquantitative technique. No growth was observed on any of the 25 negative control drapes. In contrast, 100% of preoperative and 96% of postoperative positive controls demonstrated obvious contamination. In the postoperative group, all 7 sites of evaluation were found to be contaminated with rates of 12% to 44%. Four of the 7 evaluated locations were found to have significant contamination rates compared with negative controls, including the shafts of the optic eyepieces on the main surgeon side (24%, P = 0.022), "forehead" portion on both the main surgeon (24%, P = 0.022) and assistant sides (28%, P = 0.010), and "overhead" portion of the drape (44%, P = 0.0002). Bacterial contamination of the operative microscope was found to be significant after spine surgery. Contamination was more common around the optic eyepieces, likely due to inadvertent touching of unsterile portions. Similarly, all regions above the eyepieces also have a propensity for contamination because of unknown contact

  15. Properties of multiple field ion emitters of tungsten and a simple method for improving their ionization efficiency

    International Nuclear Information System (INIS)

    Okuyama, F.; Beckey, H.D.

    1978-01-01

    The ion emission properties of the multiple tungsten emitters developed recently for field ionization mass spectrometry were investigated with the aid of a sector type mass spectrometer at emitter-cathode voltages of 10-15 kV using acetone, n-heptane and benzene as test substances. The emitters, which comprised a 10-μm tungsten filament bearing thickly arrayed microneedles of tungsten, produced very weak and unstable signals at voltages of about 10 kV, but increasing the voltage to 14 kV led to intensifying ion currents high enough to yield mass spectra of satisfactory quality. During the course of the experiments, it was observed that nucleating tungsten carbide particles on the emitter surface by means of a high-field chemical reaction with benzene vapours can significanlty promote the field ionization of gas molecules, presumably as a result of the field enhancement resulting from roughening of the surface. (Auth.)

  16. 21 CFR 884.6190 - Assisted reproductive microscopes and microscope accessories.

    Science.gov (United States)

    2010-04-01

    ... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction.... Assisted reproduction microscopes and microscope accessories (excluding microscope stage warmers, which are classified under assisted reproduction accessories) are optical instruments used to enlarge images of gametes...

  17. Shear Brillouin light scattering microscope.

    Science.gov (United States)

    Kim, Moonseok; Besner, Sebastien; Ramier, Antoine; Kwok, Sheldon J J; An, Jeesoo; Scarcelli, Giuliano; Yun, Seok Hyun

    2016-01-11

    Brillouin spectroscopy has been used to characterize shear acoustic phonons in materials. However, conventional instruments had slow acquisition times over 10 min per 1 mW of input optical power, and they required two objective lenses to form a 90° scattering geometry necessary for polarization coupling by shear phonons. Here, we demonstrate a confocal Brillouin microscope capable of detecting both shear and longitudinal phonons with improved speeds and with a single objective lens. Brillouin scattering spectra were measured from polycarbonate, fused quartz, and borosilicate in 1-10 s at an optical power level of 10 mW. The elastic constants, phonon mean free path and the ratio of the Pockels coefficients were determined at microscopic resolution.

  18. Differential magnetic force microscope imaging.

    Science.gov (United States)

    Wang, Ying; Wang, Zuobin; Liu, Jinyun; Hou, Liwei

    2015-01-01

    This paper presents a method for differential magnetic force microscope imaging based on a two-pass scanning procedure to extract differential magnetic forces and eliminate or significantly reduce background forces with reversed tip magnetization. In the work, the difference of two scanned images with reversed tip magnetization was used to express the local magnetic forces. The magnetic sample was first scanned with a low lift distance between the MFM tip and the sample surface, and the magnetization direction of the probe was then changed after the first scan to perform the second scan. The differential magnetic force image was obtained through the subtraction of the two images from the two scans. The theoretical and experimental results have shown that the proposed method for differential magnetic force microscope imaging is able to reduce the effect of background or environment interference forces, and offers an improved image contrast and signal to noise ratio (SNR). © Wiley Periodicals, Inc.

  19. Infrared up-conversion microscope

    DEFF Research Database (Denmark)

    2014-01-01

    There is presented an up-conversion infrared microscope (110) arranged for imaging an associated object (130), wherein the up-conversion infrared microscope (110) comprises a non-linear crystal (120) arranged for up-conversion of infrared electromagnetic radiation, and wherein an objective optical...... component (100) has an entrance pupil with a first diameter D1, and an optical component system which is arranged for forming an external image (136) of the back-focal plane (132) of the objective optical component (100), which has a diameter (given by the diameter of a circle enclosing all optical paths...... at the plane of the 10 external image) which is denominated D2 and wherein D1 is larger than a second diameter D2....

  20. Duties to Extraterrestrial Microscopic Organisms

    Science.gov (United States)

    Cockell, C. S.

    Formulating a normative axiology for the treatment of extraterrestrial microscopic organisms, should they ever be found, requires an extension of environmental ethics to beyond the Earth. Using an ethical framework for the treatment of terrestrial micro-organisms, this paper elaborates a similar ethic for the treatment of extraterrestrial microscopic organisms. An ethic of `teloempathy' allows for the moral considerability of any organism that has `interests', based on rudimentary qualities of conativism, and therefore allows for an identical treatment of all life, related or not related to life on Earth. Although, according to this ethic, individual extraterrestrial microscopic organisms have a good of their own and even `rights', at this level the ethic can only be theoretical, allowing for the inevitable destruction of many individual organisms during the course of human exploratory missions, similarly to the daily destruction of microbes by humans on Earth. A holistic teloempathy, an operative ethic, not only provides a framework for human exploration, but it also has important implications for planetary protection and proposals to implement planetary-scale atmospheric alterations on other bodies. Even prior to the discovery of extraterrestrial life, or the discovery of a complete absence of such life, this exercise yields important insights into the moral philosophy that guides our treatment of terrestrial micro-organisms.

  1. The outcomes of overlay myringoplasty: Endoscopic versus microscopic approach.

    Science.gov (United States)

    Plodpai, Yuvatiya; Paje, Nanatphong

    To investigate the outcomes of overlay myringoplasty by comparing the endoscopic versus the microscopic approach. This is a retrospective comparative study of 181 patients who underwent myringoplasty with overlay techniques between January 2010 and 2016 at Songklanagarind Hospital, Thailand. Group 1 underwent an endoscopic-assisted (n=90), and group 2 underwent the microscopic-assisted (n=91) overlay myringoplasty. The outcomes were graft take rates, the audiometric results, the need of canalplasty, complications and operative time. All patients were followed up for at least 6months. The graft take rates were 96.7% in the endoscopic group and 91.2% in the microscopic group, p=0.22. The operative time was 98.9±11.0min for the endoscopic group, and 176.6±14.9min for the microscope group, poverlay myringoplasty provided satisfactory surgical as well as audiometric outcomes when compared with the microscopic approach. The graft take rate and postoperative hearing were similar in both groups. The endoscopic approach seemed to be superior than the microscopic approach in term of operative time, complication, and no need for canalplasty. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Literature survey on microscopic friction modeling

    NARCIS (Netherlands)

    Hol, J.

    2010-01-01

    To better understand contact and friction conditions, experimental and theoretical studies have been performed in order to take microscopic dependencies into account. Friction is developed on microscopic level by adhesion between contacting asperities, the ploughing effect between asperities and the

  3. Sub-nanosecond time-resolved near-field scanning magneto-optical microscope.

    Science.gov (United States)

    Rudge, J; Xu, H; Kolthammer, J; Hong, Y K; Choi, B C

    2015-02-01

    We report on the development of a new magnetic microscope, time-resolved near-field scanning magneto-optical microscope, which combines a near-field scanning optical microscope and magneto-optical contrast. By taking advantage of the high temporal resolution of time-resolved Kerr microscope and the sub-wavelength spatial resolution of a near-field microscope, we achieved a temporal resolution of ∼50 ps and a spatial resolution of microscope, the magnetic field pulse induced gyrotropic vortex dynamics occurring in 1 μm diameter, 20 nm thick CoFeB circular disks has been investigated. The microscope provides sub-wavelength resolution magnetic images of the gyrotropic motion of the vortex core at a resonance frequency of ∼240 MHz.

  4. A Student-Built Scanning Tunneling Microscope

    Science.gov (United States)

    Ekkens, Tom

    2015-01-01

    Many introductory and nanotechnology textbooks discuss the operation of various microscopes including atomic force (AFM), scanning tunneling (STM), and scanning electron microscopes (SEM). In a nanotechnology laboratory class, students frequently utilize microscopes to obtain data without a thought about the detailed operation of the tool itself.…

  5. Microscopic Analysis of Activated Sludge. Training Manual.

    Science.gov (United States)

    Office of Water Program Operations (EPA), Cincinnati, OH. National Training and Operational Technology Center.

    This training manual presents material on the use of a compound microscope to analyze microscope communities, present in wastewater treatment processes, for operational control. Course topics include: sampling techniques, sample handling, laboratory analysis, identification of organisms, data interpretation, and use of the compound microscope.…

  6. Master equations in the microscopic theory of nuclear collective dynamics

    International Nuclear Information System (INIS)

    Matsuo, M.; Sakata, F.; Marumori, T.; Zhuo, Y.

    1988-07-01

    In the first half of this paper, the authors describe briefly a recent theoretical approach where the mechanism of the large-amplitude dissipative collective motions can be investigated on the basis of the microscopic theory of nuclear collective dynamics. Namely, we derive the general coupled master equations which can disclose, in the framework of the TDHF theory, not only non-linear dynamics among the collective and the single-particle modes of motion but also microscopic dynamics responsible for the dissipative processes. In the latter half, the authors investigate, without relying on any statistical hypothesis, one possible microscopic origin which leads us to the transport equation of the Fokker-Planck type so that usefullness of the general framework is demonstrated. (author)

  7. Microscopic structure for light nuclei

    International Nuclear Information System (INIS)

    Sharma, V.K.

    1995-01-01

    The microscopic structure for light nuclei e.g. 4 He, 7 Li and 8 Be is considered in the frame work of the generator coordinate method (GCM). The physical interpretation of our GCM is also discussed. The GC amplitudes are used to calculate the various properties like charge and magnetic RMS radii, form factors, electromagnetic moments, astrophysical S-factor, Bremsstrahlung weighted cross sections, relative wavefunctions and vertex functions etc. All the calculated quantities agree well with the values determined experimentally. (author). 30 refs., 10 figs., 2 tabs

  8. Microscopic structure of liquid hydrogen

    CERN Document Server

    Zoppi, M

    2003-01-01

    Hydrogen makes the simplest molecular liquid. Nonetheless, due to several different reasons, measuring its microscopic structure has been one of the most challenging tasks in neutron diffraction experiments. The recent development of modern pulsed neutron sources triggered a renewed experimental interest which, in turn, led to new knowledge and also to a more effective use of the classic reactor-based experimental data. The contemporary development of quantum mechanical computer simulation techniques, and a critical comparison among the results of different experiments using steady and pulsed neutron sources, resulted in a quantitatively reliable solution of the problem. (topical review)

  9. Wolter x-ray microscope calibration

    International Nuclear Information System (INIS)

    Gerassimenko, M.

    1986-01-01

    A 22 x Wolter microscope was calibrated after several months of operation in the Lawrence Livermore National Laboratory (LLNL) Inertial Confinement Fusion program. Placing a point x-ray source at the microscope focus, I recorded the image plane spectrum, as well as the direct spectrum, and from the ratio of these two spectra derived an accurate estimate of the microscope solid angle in the 1-4 keV range. The solid angle was also calculated using the microscope geometry and composition. Comparison of this calculated value with the solid angle that was actually measured suggests contamination of the microscope surface

  10. Wolter x-ray microscope calibration

    International Nuclear Information System (INIS)

    Gerassimenko, M.

    1986-06-01

    A 22 x Wolter microscope was calibrated after several months of operation in the Lawrence Livermore National laboratory (LLNL) Inertial Confinement Fusion program. Placing a point x-ray source at the microscope focus, I recorded the image plane spectrum, as well as the direct spectrum, and from the ratio of these two spectra derived an accurate estimate of the microscope solid angle in the 1 to 4 keV range. The solid angle was also calculated using the microscope geometry and composition. Comparison of this calculated value with the solid angle that was actually measured suggests contamination of the microscope surface

  11. The illumination characteristics of operative microscopes.

    Science.gov (United States)

    Schutt, Christopher A; Redding, Brandon; Cao, Hui; Michaelides, Elias

    2015-01-01

    Modern operative microscopes use light sources which possess the power to severely damage underlying tissue. Currently, manufacturers provide a safety warning of this possibility. However, they are unable to suggest specific settings due to a stated "lack of scientific publications on this topic". We aim to radiometrically evaluate multiple otologic microscopes at variables which effect irradiance in order to determine reference emissions levels and provide guidelines for improved intraoperative safety. The optical radiance of four otologic microscopes was evaluated at variable field illumination sizes (spot size), intensity settings and working distances. The spectral emission of each microscope was separately measured. The energy absorbed in skin with representative properties was then calculated as a function of time for each microscope by accounting for the emission spectrum of the microscope and the absorption spectrum of skin. Microscopes showed a wide range of optical radiance based on model, spots size, intensity setting and working distances. Spectral emission of all four microscopes was centered in the visible spectrum with minimal ultraviolet or infrared contribution. A large amount of energy is absorbed by skin during usage of operative microscopes. The highest calculated absorption at 200 min of use was 736.26 J/cm(2). Operative microscopes have the ability to cause patient morbidity secondary to the energy they impart. In an effort to decrease potential injury we recommend that physicians be aware of their microscopes properties and how to control variables which effect irradiance of the skin. Published by Elsevier Inc.

  12. Robotic autopositioning of the operating microscope.

    Science.gov (United States)

    Oppenlander, Mark E; Chowdhry, Shakeel A; Merkl, Brandon; Hattendorf, Guido M; Nakaji, Peter; Spetzler, Robert F

    2014-06-01

    Use of the operating microscope has become pervasive since its introduction to the neurosurgical world. Neuronavigation fused with the operating microscope has allowed accurate correlation of the focal point of the microscope and its location on the downloaded imaging study. However, the robotic ability of the Pentero microscope has not been utilized to orient the angle of the microscope or to change its focal length to hone in on a predefined target. To report a novel technology that allows automatic positioning of the operating microscope onto a set target and utilization of a planned trajectory, either determined with the StealthStation S7 by using preoperative imaging or intraoperatively with the microscope. By utilizing the current motorized capabilities of the Zeiss OPMI Pentero microscope, a robotic autopositioning feature was developed in collaboration with Surgical Technologies, Medtronic, Inc. (StealthStation S7). The system is currently being tested at the Barrow Neurological Institute. Three options were developed for automatically positioning the microscope: AutoLock Current Point, Align Parallel to Plan, and Point to Plan Target. These options allow the microscope to pivot around the lesion, hover in a set plane parallel to the determined trajectory, or rotate and point to a set target point, respectively. Integration of automatic microscope positioning into the operative workflow has potential to increase operative efficacy and safety. This technology is best suited for precise trajectories and entry points into deep-seated lesions.

  13. Microscopical advances in assisted reproduction.

    Science.gov (United States)

    Baccetti, B

    2004-01-01

    In a series of papers carried out by this laboratory it was demonstrated that the quality of sterile males sperm, assessed submicroscopically and mathematically, is closely correlated with the success of the various procedures of assisted reproduction. If we attempt to select hypothetically optimal spermatozoa destined to the ICSI by light inverted microscopy, a considerable amount of ultrastructural information is lost and our selection is merely based on the motility. In this study we apply polarization microscopy to the ICSI technique, introducing polarizing and analyzing lenses in an inverted microscope model, operating in a transparent container. The retardation of the birefringence in the various organelles is evaluated by compensators, and the images are transmitted to a video system, and stored in a computer. Spermatozoa are maintained alive and perfectly motile in this polarizing inverted microscope, and the character of the birefringence is the same as in fixed and sectioned biological material examined by polarization microscopy. The birefringence of the sperm structures allows a sperm analysis closer to TEM than to phase contrast light microscopy analysis.

  14. Inquiry based learning with a virtual microscope

    Science.gov (United States)

    Kelley, S. P.; Sharples, M.; Tindle, A.; Villasclaras-Fernández, E.

    2012-12-01

    As part of newly funded initiative, the Wolfson OpenScience Laboratory, we are linking a tool for inquiry based learning, nQuire (http://www.nquire.org.uk) with the virtual microscope for Earth science (http://www.virtualmicroscope.co.uk) to allow students to undertake projects and gain from inquiry based study thin sections of rocks without the need for a laboratory with expensive petrological microscopes. The Virtual Microscope (VM) was developed for undergraduate teaching of petrology and geoscience, allowing students to explore rock hand specimens and thin sections in a browser window. The system is based on HTML5 application and allows students to scan and zoom the rocks in a browser window, view in ppl and xpl conditions, and rotate specific areas to view birefringence and pleochroism. Importantly the VM allows students to gain access to rare specimens such as Moon rocks that might be too precious to suffer loss or damage. Experimentation with such specimens can inspire the learners' interest in science and allows them to investigate relevant science questions. Yet it is challenging for learners to engage in scientific processes, as they may lack scientific investigation skills or have problems in planning their activities; for teachers, managing inquiry activities is a demanding task (Quintana et al., 2004). To facilitate the realization of inquiry activities, the VM is being integrated with the nQuire tool. nQuire is a web tool that guides and supports students through the inquiry process (Mulholland et al., 2011). Learners are encouraged to construct their own personally relevant hypothesis, pose scientific questions, and plan the method to answer them. Then, the system enables users to collect and analyze data, and share their conclusions. Teachers can monitor their students' progress through inquiries, and give them access to new parts of inquiries as they advance. By means of the integration of nQuire and the VM, inquiries that involve collecting data

  15. microscopical analysis and quality status of honey from ...

    African Journals Online (AJOL)

    investigated. About 75 honey samples from the three zones each of the five states of the. Southeastern zone of Nigeria were collected and tested upon for moisture status and pollen concentration and sedimentation. From the microscopical analysis of the samples, Croton species were found to be predominant accounting ...

  16. Carriage of sub-microscopic sexual and asexual Plasmodium ...

    African Journals Online (AJOL)

    SUMMARY. Background: We investigated the prevalence of sub-microscopic Plasmodium falciparum infections and gameto- cyte carriage in asymptomatic individuals in Navrongo in northern Ghana, an area of seasonal malaria transmission. Design: A cross sectional study of 209 randomly selected participants of all ...

  17. Microscopic picture of the aqueous solvation of glutamic acid

    NARCIS (Netherlands)

    Leenders, E.J.M.; Bolhuis, P.G.; Meijer, E.J.

    2008-01-01

    We present molecular dynamics simulations of glutamic acid and glutamate solvated in water, using both density functional theory (DFT) and the Gromos96 force field. We focus on the microscopic aspects of the solvation−particularly on the hydrogen bond structures and dynamics−and investigate the

  18. Macroscopic and microscopic magnetism of metal-metalloid amorphous alloys

    International Nuclear Information System (INIS)

    Vasconcellos, M.A.Z.; Fichtner, P.F.P.; Livi, F.P.; Costa, M.I. da; Baibich, M.N.

    1984-01-01

    In this paper is investigated the interrelation between macroscopic and microscopic magnetic phenomena using experimetnal data from Moessbauer effect and the magnetization of layers of amorphous (Fe 1-x Ni x ) 80 B 20 . The Moessbauer effect measurement show a distribution of hyperfine fields in Fe site as well as a likely distribution of isomeric shifts (M.W.O.) [pt

  19. New Scanning Electron Microscope Used for Cryogenic Tensile Testing

    CERN Multimedia

    Maximilien Brice

    2013-01-01

    At CERN engineering department's installation for cryogenic tensile testing, the new scanning electron microscope (SEM) allows for detailed optical observations to be carried out. Using the SEM, surface coatings and tensile properties of materials can investigated in order to better understand how they behave under different conditions.

  20. Dopant profiling with the scanning electron microscope

    CERN Document Server

    Elliott, S L

    2001-01-01

    This dissertation is a detailed study of dopant profiling with the scanning electron microscope (SEM) using secondary electrons. The technique has been applied to a wide variety of doped silicon, gallium arsenide and gallium nitride semiconductor test structures as well as a metal-oxide field effect transistor and several light emitting diodes. A concise set of guide-lines are provided for users of this technique, including the optimum SEM operating conditions that should be used for maximum contrast, an image manipulation procedure, and the resolution and sensitivity limits that can be expected. Dopant contrast observed with the SEM has been studied over the past few years by a number of researchers, and a theory for the contrast has evolved. This theory considers the patch fields outside the specimen to be the dominant factor determining the secondary electron intensity. In this dissertation the contrast mechanism has been further investigated by examining the contrast at different temperatures and after su...

  1. Microscopic theory of one-body dissipation

    International Nuclear Information System (INIS)

    Koonin, S.E.; Randrup, J.; Hatch, R.; Kolomietz, V.

    1977-01-01

    A microscopic theory is developed for nuclear collective motion in the limit of a long nuclear mean-free path. Linear response techniques are applied to an independent particle model and expressions for the collective kinetic energy and rate of energy dissipation are obtained. For leptodermous systems, these quantities are characterized by mass and dissipation kernels coupling the velocities at different points on the nuclear surface. In a classical treatment, the kernels are given in terms of nucleon trajectories within the nuclear shape. In a quantal treatment, the dissipation kernel is related to the nuclear Green function. The spatial and thermal properties of the kernels are investigated. Corrections for the diffuseness of the potential and shell effects are also discussed. (Auth.)

  2. Microscopic evaluation and physiochemical analysis of Dillenia indica leaf.

    Science.gov (United States)

    Kumar, S; Kumar, V; Prakash, O M

    2011-10-01

    To study detail microscopic evaluation and physiochemical analysis of Dillenia indica (D. indica) leaf. Fresh leaf sample and dried power of the leaf were studied macroscopically and microscopically. Preliminary phytochemical investigation of plant material was done. Other WHO recommended parameters for standardizations were also performed. The detail microscopy revealed the presence of anomocytic stomata, unicellular trichome, xylem fibres, calcium oxalate crystals, vascular bundles, etc. Leaf constants such as stomatal number, stomatal index, vein-islet number and veinlet termination numbers were also measured. Physiochemical parameters such as ash values, loss on drying, extractive values, percentage of foreign matters, swelling index, etc. were also determined. Preliminary phytochemical screening showed the presence of steroids, terpenoids, glycosides, fatty acids, flavonoids, phenolic compounds and carbohydrates. The microscopic and physiochemical analysis of the D. indica leaf is useful in standardization for quality, purity and sample identification.

  3. Design of a transmission electron positron microscope

    International Nuclear Information System (INIS)

    Doyama, Masao; Inoue, M.; Kogure, Y.; Hayashi, Y.; Yoshii, T.; Kurihara, T.; Tsuno, K.

    2003-01-01

    This paper reports the plans and design of positron-electron microscopes being built at KEK (High Energy Accelerator Research Organization), Tsukuba, Japan. A used electron microscope is altered. The kinetic energies of positrons produced by accelerators or by nuclear decays are not a unique value but show a spread over in a wide range. Positron beam is guided to a transmission electron microscope (JEM100SX). Positrons are moderated by a tungsten foil, are accelerated and are focused on a nickel sheet. The monochromatic focused beam is injected into an electron microscope. The focusing and aberration of positrons are the same as electrons in a magnetic system which are used in commercial electron microscopes. Imaging plates are used to record positron images for the transmission electron microscope. (author)

  4. Testing microscopes between market and scientific strategies

    OpenAIRE

    Ratcliff, Marc

    2007-01-01

    This paper claims that the testing of microscopes during the eighteenth century reveals specific types of interaction between makers and users and links between scientific and economic interests. Basic procedures for the comparison and test of microscopes existed already in the Enlightenment although many historians thought that these were invented during the nineteenth century. The paper discusses three kinds of tests, advertising, the admission of a microscope in the laboratory, and finally...

  5. Calibrated atomic force microscope measurements of vickers hardness indentations and tip production and characterisation for scanning tunelling microscope

    DEFF Research Database (Denmark)

    Jensen, Carsten P.

    Calibrated atomic force microscope measurements of vickers hardness indentations and tip production and characterisation for scanning tunelling microscope......Calibrated atomic force microscope measurements of vickers hardness indentations and tip production and characterisation for scanning tunelling microscope...

  6. Microscopic description of magnetized plasma: quasiparticle concept

    International Nuclear Information System (INIS)

    Sosenko, P.P.; Decyk, V.K.

    1993-01-01

    A quasiparticle concept is developed systematically, from first principles, within the context of microscopic description of magnetized plasma. It is argued that the zeroth velocity-gyroangle harmonic of the microscopic particle distribution function under the gyrokinetic change of variables can be taken as a microscopic quasi-particle density in a reduced phase space. The nature of quasiparticles is discussed and equations of their motion are derived within both exact and reduced microscopic descriptions. The reduced one employs explicitly the separation of interesting time scales. (orig.)

  7. Foldscope: origami-based paper microscope.

    Directory of Open Access Journals (Sweden)

    James S Cybulski

    Full Text Available Here we describe an ultra-low-cost origami-based approach for large-scale manufacturing of microscopes, specifically demonstrating brightfield, darkfield, and fluorescence microscopes. Merging principles of optical design with origami enables high-volume fabrication of microscopes from 2D media. Flexure mechanisms created via folding enable a flat compact design. Structural loops in folded paper provide kinematic constraints as a means for passive self-alignment. This light, rugged instrument can survive harsh field conditions while providing a diversity of imaging capabilities, thus serving wide-ranging applications for cost-effective, portable microscopes in science and education.

  8. Complex composition film condensation in the sluice device of an electron microscope

    International Nuclear Information System (INIS)

    Kukuev, V.I.; Lesovoj, M.V.; Vlasov, D.A.; Malygin, M.V.; Domashevskaya, Eh.P.; Tomashpol'skij, Yu.Ya.

    1994-01-01

    Based on the sluice device of an electron microscope a system is developed for material laser evaporation and vapor condensation on a substrate, situated in the microscope specimen holder. Substrate heating by laser radiation to 100 deg C is used. The system is applied for investigating growth of high-temperature superconductor films

  9. Microscopic neutron investigation of the Abrikosov state of high ...

    Indian Academy of Sciences (India)

    Abstract. Using small angle neutron scattering we have been able to observe for the first time a well-defined vortex lattice (VL) structure both in the hole-doped LSCO and electron-doped NCCO superconductors. Our measurements on optimally doped LSCO reveal the existence of a magnetic field-induced phase transition ...

  10. Microscopic investigation of the 12C + 12C interaction

    International Nuclear Information System (INIS)

    Baye, D.; Pecher, N.; Brussels Univ.

    1982-01-01

    The 12 C + 12 C system is studied in the framework of the generator coordinate method. Each 12 C nucleus is described by a closed psub(3/2) subshell. Phase shifts and resonances are determined for several effective two-body interactions involving a spin-orbit term. The existence and properties of simple local equivalent potentials for the 12 C + 12 C collision are discussed. The 12 C + 12 C system is too light to be well described by potentials independent of the angular momentum or weakly dependent on it. (orig.)

  11. Microscopic neutron investigation of the Abrikosov state of high ...

    Indian Academy of Sciences (India)

    reveal the existence of a magnetic field-induced phase transition from a hexagonal to a square coordination of the ... Introduction. Apart from the unusual electronic and magnetic behaviour of the cuprate high- temperature ... are visualized in figure 3. In order to lift this apparent contradiction, Nakai et al [8], based on photoe-.

  12. Scanning Microscopes Using X Rays and Microchannels

    Science.gov (United States)

    Wang, Yu

    2003-01-01

    Scanning microscopes that would be based on microchannel filters and advanced electronic image sensors and that utilize x-ray illumination have been proposed. Because the finest resolution attainable in a microscope is determined by the wavelength of the illumination, the xray illumination in the proposed microscopes would make it possible, in principle, to achieve resolutions of the order of nanometers about a thousand times as fine as the resolution of a visible-light microscope. Heretofore, it has been necessary to use scanning electron microscopes to obtain such fine resolution. In comparison with scanning electron microscopes, the proposed microscopes would likely be smaller, less massive, and less expensive. Moreover, unlike in scanning electron microscopes, it would not be necessary to place specimens under vacuum. The proposed microscopes are closely related to the ones described in several prior NASA Tech Briefs articles; namely, Miniature Microscope Without Lenses (NPO-20218), NASA Tech Briefs, Vol. 22, No. 8 (August 1998), page 43; and Reflective Variants of Miniature Microscope Without Lenses (NPO-20610), NASA Tech Briefs, Vol. 26, No. 9 (September 2002) page 6a. In all of these microscopes, the basic principle of design and operation is the same: The focusing optics of a conventional visible-light microscope are replaced by a combination of a microchannel filter and a charge-coupled-device (CCD) image detector. A microchannel plate containing parallel, microscopic-cross-section holes much longer than they are wide is placed between a specimen and an image sensor, which is typically the CCD. The microchannel plate must be made of a material that absorbs the illuminating radiation reflected or scattered from the specimen. The microchannels must be positioned and dimensioned so that each one is registered with a pixel on the image sensor. Because most of the radiation incident on the microchannel walls becomes absorbed, the radiation that reaches the

  13. A transmission positron microscope and a scanning positron microscope being built at KEK, Japan

    International Nuclear Information System (INIS)

    Doyama, M.; Inoue, M.; Kogure, Y.; Kurihara, T.; Yagishita, A.; Shidara, T.; Nakahara, K.; Hayashi, Y.; Yoshiie, T.

    2001-01-01

    This paper reports the plans of positron microscopes being built at KEK (High Energy Accelerator Research Organization), Tsukuba, Japan improving used electron microscopes. The kinetic energies of positron produced by accelerators or by nuclear decays have not a unique value but show a spread over in a wide range. Positron beam will be guided near electron microscopes, a transmission electron microscope (JEM100S) and a scanning electron microscope (JSM25S). Positrons are slowed down by a tungsten foil, accelerated and focused on a nickel sheet. The monochromatic focused beam will be injected into an electron microscope. The focusing of positrons and electrons is achieved by magnetic system of the electron microscopes. Imaging plates are used to record positron images for the transmission electron microscope. (orig.)

  14. Spectral Interferometry with Electron Microscopes.

    Science.gov (United States)

    Talebi, Nahid

    2016-09-21

    Interference patterns are not only a defining characteristic of waves, but also have several applications; characterization of coherent processes and holography. Spatial holography with electron waves, has paved the way towards space-resolved characterization of magnetic domains and electrostatic potentials with angstrom spatial resolution. Another impetus in electron microscopy has been introduced by ultrafast electron microscopy which uses pulses of sub-picosecond durations for probing a laser induced excitation of the sample. However, attosecond temporal resolution has not yet been reported, merely due to the statistical distribution of arrival times of electrons at the sample, with respect to the laser time reference. This is however, the very time resolution which will be needed for performing time-frequency analysis. These difficulties are addressed here by proposing a new methodology to improve the synchronization between electron and optical excitations through introducing an efficient electron-driven photon source. We use focused transition radiation of the electron as a pump for the sample. Due to the nature of transition radiation, the process is coherent. This technique allows us to perform spectral interferometry with electron microscopes, with applications in retrieving the phase of electron-induced polarizations and reconstructing dynamics of the induced vector potential.

  15. Hamiltonian mechanics limits microscopic engines

    Science.gov (United States)

    Anglin, James; Gilz, Lukas; Thesing, Eike

    2015-05-01

    We propose a definition of fully microscopic engines (micro-engines) in terms of pure mechanics, without reference to thermodynamics, equilibrium, or cycles imposed by external control, and without invoking ergodic theory. This definition is pragmatically based on the observation that what makes engines useful is energy transport across a large ratio of dynamical time scales. We then prove that classical and quantum mechanics set non-trivial limits-of different kinds-on how much of the energy that a micro-engine extracts from its fuel can be converted into work. Our results are not merely formal; they imply manageable design constraints on micro-engines. They also suggest the novel possibility that thermodynamics does not emerge from mechanics in macroscopic regimes, but rather represents the macroscopic limit of a generalized theory, valid on all scales, which governs the important phenomenon of energy transport across large time scale ratios. We propose experimental realizations of the dynamical mechanisms we identify, with trapped ions and in Bose-Einstein condensates (``motorized bright solitons'').

  16. Mice embryology: a microscopic overview.

    Science.gov (United States)

    Salvadori, Maria Letícia Baptista; Lessa, Thais Borges; Russo, Fabiele Baldino; Fernandes, Renata Avancini; Kfoury, José Roberto; Braga, Patricia Cristina Baleeiro Beltrão; Miglino, Maria Angélica

    2012-10-01

    In this work, we studied the embryology of mice of 12, 14, and 18 days of gestation by gross observation, light microscopy, and scanning electron microscopy. Grossly, the embryos of 12 days were observed in C-shaped region of the brain, eye pigmentation of the retina, first, second, and third pharyngeal arches gill pit nasal region on the fourth ventricle brain, cervical curvature, heart, liver, limb bud thoracic, spinal cord, tail, umbilical cord, and place of the mesonephric ridge. Microscopically, the liver, cardiovascular system and spinal cord were observed. In the embryo of 14 days, we observed structures that make up the liver and heart. At 18 days of gestation fetuses, it was noted the presence of eyes, mouth, and nose in the cephalic region, chest and pelvic region with the presence of well-developed limbs, umbilical cord, and placenta. Scanning electron microscopy in 18 days of gestation fetuses evidenced head, eyes closed eyelids, nose, vibrissae, forelimb, heart, lung, kidney, liver, small bowel, diaphragm, and part of the spine. The results obtained in this work describe the internal and external morphology of mice, provided by an integration of techniques and review of the morphological knowledge of the embryonic development of this species, as this animal is of great importance to scientific studies. Copyright © 2012 Wiley Periodicals, Inc.

  17. Multibeam scanning electron microscope : Experimental results

    NARCIS (Netherlands)

    Mohammadi-Gheidari, A.; Hagen, C.W.; Kruit, P.

    2010-01-01

    The authors present the first results obtained with their multibeam scanning electron microscope. For the first time, they were able to image 196 (array of 14×14) focused beams of a multielectron beam source on a specimen using single beam scanning electron microscope (SEM) optics. The system

  18. Major Components of the Light Microscope

    OpenAIRE

    Centonze Frohlich, Victoria

    2008-01-01

    The light microscope is a basic tool for the cell biologist, who should have a thorough understanding of how it works, how it should be aligned for different applications, and how it should be maintained as required to obtain maximum image-forming capacity and resolution. The components of the microscope are described in detail here.

  19. Major components of the light microscope.

    Science.gov (United States)

    Centonze Frohlich, Victoria

    2008-07-30

    The light microscope is a basic tool for the cell biologist, who should have a thorough understanding of how it works, how it should be aligned for different applications, and how it should be maintained as required to obtain maximum image-forming capacity and resolution. The components of the microscope are described in detail here.

  20. Microscopic colitis : an unfamiliar but treatable disease

    NARCIS (Netherlands)

    van der Wouden, E. J.; Karrenbeld, A.; Kleibeuker, J. H.; Dijkstra, G.

    Chronic diarrhoea is a frequent complaint in clinical practice. Microscopic colitis is the cause of this symptom in 10% of these cases and the prevalence is rising. To exclude microscopic colitis a colonoscopy with multiple biopsies of different regions of the colon is mandatory. A sigmoidoscopy

  1. A microscopic model of triangular arbitrage

    Science.gov (United States)

    Aiba, Yukihiro; Hatano, Naomichi

    2006-11-01

    We introduce a microscopic model which describes the dynamics of each dealer in multiple foreign exchange markets, taking account of the triangular arbitrage transaction. The model reproduces the interaction among the markets well. We explore the relation between the parameters of the present microscopic model and the spring constant of a macroscopic model that we proposed previously.

  2. Quantum theory and microscopic mechanics. I

    International Nuclear Information System (INIS)

    Yussouff, M.

    1984-08-01

    The need for theoretical descriptions and experimental observations on 'small' individual systems is emphasized. It is shown that the mathematical basis for microscopic mechanics is very simple in one dimension. The square well problem is discussed to clarify general points about stationary states and the continuity of (p'/p) across potential boundaries in the applications of microscopic mechanics. (author)

  3. Polymerized LB Films Imaged with a Combined Atomic Force Microscope-Fluorescence Microscope

    NARCIS (Netherlands)

    Putman, C.A.J.; Putman, Constant A.J.; Hansma, Helen G.; Gaub, Hermann E.; Hansma, Paul K.

    1992-01-01

    The first results obtained with a new stand-alone atomic force microscope (AFM) integrated with a standard Zeiss optical fluorescence microscope are presented. The optical microscope allows location and selection of objects to be imaged with the high-resolution AFM. Furthermore, the combined

  4. Performance verification of focus variation and confocal microscopes measuring tilted ultra-fine surfaces

    DEFF Research Database (Denmark)

    Quagliotti, Danilo; Baruffi, Federico; Tosello, Guido

    2016-01-01

    The behaviour of two optical instruments, scilicet a laser scanning confocal microscope and a focus-variation microscope, was investigated considering measurements of tilted surfaces. The measured samples were twelve steel artefacts for mould surface finish reference, covering Sa roughness...... parameter in the range (101—103) nm. The 3D surface texture parameters considered were Sa, Sq and Sdq. The small working distance of the confocal microscope objectives influenced the measurement setup, preventing from selecting a high tilting angle. The investigation was carried out comparing measurements...... of flat surfaces (0° tilt) with measurements of 12.5° tilted surfaces. The confocal microscope results showed a high sensitivity to tilting due to the laser beam reflection on the metal surfaces. The focus variation microscope results were more robust with respect to the considered angular variation...

  5. Cathodoluminescence in the scanning transmission electron microscope.

    Science.gov (United States)

    Kociak, M; Zagonel, L F

    2017-05-01

    Cathodoluminescence (CL) is a powerful tool for the investigation of optical properties of materials. In recent years, its combination with scanning transmission electron microscopy (STEM) has demonstrated great success in unveiling new physics in the field of plasmonics and quantum emitters. Most of these results were not imaginable even twenty years ago, due to conceptual and technical limitations. The purpose of this review is to present the recent advances that broke these limitations, and the new possibilities offered by the modern STEM-CL technique. We first introduce the different STEM-CL operating modes and the technical specificities in STEM-CL instrumentation. Two main classes of optical excitations, namely the coherent one (typically plasmons) and the incoherent one (typically light emission from quantum emitters) are investigated with STEM-CL. For these two main classes, we describe both the physics of light production under electron beam irradiation and the physical basis for interpreting STEM-CL experiments. We then compare STEM-CL with its better known sister techniques: scanning electron microscope CL, photoluminescence, and electron energy-loss spectroscopy. We finish by comprehensively reviewing recent STEM-CL applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Cathodoluminescence in the scanning transmission electron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Kociak, M., E-mail: mathieu.kociak@u-psud.fr [Laboratoire de Physique des Solides, Université Paris-SudParis-Sud, CNRS-UMR 8502, Orsay 91405 (France); Zagonel, L.F. [“Gleb Wataghin” Institute of Physics University of Campinas - UNICAMP, 13083-859 Campinas, São Paulo (Brazil)

    2017-05-15

    Cathodoluminescence (CL) is a powerful tool for the investigation of optical properties of materials. In recent years, its combination with scanning transmission electron microscopy (STEM) has demonstrated great success in unveiling new physics in the field of plasmonics and quantum emitters. Most of these results were not imaginable even twenty years ago, due to conceptual and technical limitations. The purpose of this review is to present the recent advances that broke these limitations, and the new possibilities offered by the modern STEM-CL technique. We first introduce the different STEM-CL operating modes and the technical specificities in STEM-CL instrumentation. Two main classes of optical excitations, namely the coherent one (typically plasmons) and the incoherent one (typically light emission from quantum emitters) are investigated with STEM-CL. For these two main classes, we describe both the physics of light production under electron beam irradiation and the physical basis for interpreting STEM-CL experiments. We then compare STEM-CL with its better known sister techniques: scanning electron microscope CL, photoluminescence, and electron energy-loss spectroscopy. We finish by comprehensively reviewing recent STEM-CL applications. - Highlights: • Reviews the field of STEM-CL. • Introduces the technical requirements and challenges for STEM-CL. • Introduces the different types of excitations probed by STEM-CL. • Gives comprehensive overview of the last fifteenth years in the field.

  7. Analysis of disruptive events and precarious situations caused by interaction with neurosurgical microscope.

    Science.gov (United States)

    Eivazi, Shahram; Afkari, Hoorieh; Bednarik, Roman; Leinonen, Ville; Tukiainen, Markku; Jääskeläinen, Juha E

    2015-07-01

    Developments in micro-neurosurgical microscopes have improved operating precision and ensured the quality of outcomes. Using the stereoscopic magnified view, however, necessitates frequent manual adjustments to the microscope during an operation. This article reports on an investigation of the interaction details concerning a state-of-the-art micro-neurosurgical microscope. The video data from detailed observations of neurosurgeons' interaction patterns with the microscope were analysed to examine disruptive events caused by adjusting the microscope. The primary findings show that interruptions caused by adjusting the microscope handgrips and mouth switch prolong the surgery time up to 10%. Surgeons, we observed, avoid interaction with the microscope's controls, settings, and configurations by working at the edge of the view, operating on a non-focused view, and assuming unergonomic body postures. The lack of an automatic method for adjusting the microscope is a major problem that causes interruptions during micro-neurosurgery. From this understanding of disruptive events, we discuss the opportunities and limitations of interactive technologies that aim to reduce the frequency or shorten the duration of interruptions caused by microscope adjustment.

  8. Development and applications of the positron microscope

    International Nuclear Information System (INIS)

    1991-01-01

    Progress on the positron microscope during the past year has been steady, and we currently project that initial microscope images can be collected during mid to late summer of 1992. Work during the year has mainly been divided among four areas of effort: hardware construction; power supply and control system development; radioactive source fabrication; and planning of initial experimental projects. Details of progress in these areas will be given below. An initial optical design of the microscope was completed during 1990, but during the past year, significant improvements have been made to this design, and several limiting cases of microscope performance have been evaluated. The results of these evaluations have been extremely encouraging, giving us strong indications that the optical performance of the microscope will be better than originally anticipated. In particular, we should be able to explore ultimate performance capabilities of positron microscopy using our currently planned optical system, with improvements only in the image detector system, and the positron-source/moderator configuration. We should be able to study imaging reemission microscopy with resolutions approaching 10 Angstrom and be able to produce beam spots for rastered microscope work with diameters below the 1000 Angstrom diffusion limit. Because of these exciting new possibilities, we have decided to upgrade several microscope subsystems to levels consistent with ultimate performance earlier in our construction schedule than we had previously intended. In particular, alignment facilities in the optical system, vibration isolation, and power supply and control system flexibility have all been upgraded in their design over the past year

  9. Atomic Force Microscope Mediated Chromatography

    Science.gov (United States)

    Anderson, Mark S.

    2013-01-01

    The atomic force microscope (AFM) is used to inject a sample, provide shear-driven liquid flow over a functionalized substrate, and detect separated components. This is demonstrated using lipophilic dyes and normal phase chromatography. A significant reduction in both size and separation time scales is achieved with a 25-micron-length column scale, and one-second separation times. The approach has general applications to trace chemical and microfluidic analysis. The AFM is now a common tool for ultra-microscopy and nanotechnology. It has also been demonstrated to provide a number of microfluidic functions necessary for miniaturized chromatography. These include injection of sub-femtoliter samples, fluidic switching, and sheardriven pumping. The AFM probe tip can be used to selectively remove surface layers for subsequent microchemical analysis using infrared and tip-enhanced Raman spectroscopy. With its ability to image individual atoms, the AFM is a remarkably sensitive detector that can be used to detect separated components. These diverse functional components of microfluidic manipulation have been combined in this work to demonstrate AFM mediated chromatography. AFM mediated chromatography uses channel-less, shear-driven pumping. This is demonstrated with a thin, aluminum oxide substrate and a non-polar solvent system to separate a mixture of lipophilic dyes. In conventional chromatographic terms, this is analogous to thin-layer chromatography using normal phase alumina substrate with sheardriven pumping provided by the AFM tip-cantilever mechanism. The AFM detection of separated components is accomplished by exploiting the variation in the localized friction of the separated components. The AFM tip-cantilever provides the mechanism for producing shear-induced flows and rapid pumping. Shear-driven chromatography (SDC) is a relatively new concept that overcomes the speed and miniaturization limitations of conventional liquid chromatography. SDC is based on a

  10. Operating microscopes: past, present, and future.

    Science.gov (United States)

    Uluç, Kutluay; Kujoth, Gregory C; Başkaya, Mustafa K

    2009-09-01

    The operating microscope is a fixture of modern surgical facilities, and it is a critically important factor in the success of many of the most complex and difficult surgical interventions used in medicine today. The rise of this key surgical tool reflects advances in understanding the principles of optics and vision that have occurred over centuries. The development of reading spectacles in the late 13th century led to the construction of early compound microscopes in the 16th and 17th centuries by Lippershey, Janssen, Galileo, Hooke, and others. Perhaps surprisingly, Leeuwenhoek's simple microscopes of this era offered improved performance over his contemporaries' designs. The intervening years saw improvements that reduced the spherical and chromatic aberrations present in compound microscopes. By the late 19th century, Carl Zeiss and Ernst Abbe ushered the compound microscope into the beginnings of the modern era of commercial design and production. The introduction of the microscope into the operating room by Nylén in 1921 initiated a revolution in surgical practice that gained momentum throughout the 1950s with multiple refinements, the introduction of the Zeiss OPMI series, and Kurze's application of the microscope to neurosurgery in 1957. Many of the refinements of the last 50 years have greatly improved the handling and practical operation of the surgical microscope, considerations which are equally important to its optical performance. Today's sophisticated operating microscopes allow for advanced real-time angiographic and tumor imaging. In this paper the authors discuss what might be found in the operating rooms of tomorrow.

  11. The Mathematical Microscope - Making the inaccessible accessible

    DEFF Research Database (Denmark)

    Ottesen, Johnny T.

    2011-01-01

      In this chapter we introduce a new term, the "Mathematical Microscope", as a method of using mathematics in accessing information about reality when this information is otherwise inaccessible. Furthermore, we discuss how models and experiments are related: none of which are important without...... the other. In the sciences and medicine, a link that is often missing in the chain of a system can be made visible with the aid of the mathematical microscope. The mathematical microscope serves not only as a lens to clarify a blurred picture but more important as a tool to unveil profound truths...

  12. Microscopes for NASA's Phoenix Mars Lander

    Science.gov (United States)

    2007-01-01

    One part of the Microscopy, Electrochemistry, and Conductivity Analyzer instrument for NASA's Phoenix Mars Lander is a pair of telescopes with a special wheel (on the right in this photograph) for presenting samples to be inspected with the microscopes. A horizontally mounted optical microscope (on the left in this photograph) and an atomic force microscope will examine soil particles and possibly ice particles. The shapes and the size distributions of soil particles may tell scientists about environmental conditions the material has experienced. Tumbling rounds the edges. Repeated wetting and freezing causes cracking. Clay minerals formed during long exposure to water have distinctive, platy particles shapes.

  13. Confocal scanning microscope for nuclear photoemulsion

    International Nuclear Information System (INIS)

    Batusov, Yu.A.; Kovalev, Yu.S.; Soroko, L.M.

    2005-01-01

    The application of the confocal scanning microscope to the objects in the nuclear photoemulsion is described. An array of 27 microtomograms of single silver grain is shown. The cross sections of the same particle track of diameter 1 μm, detected by means of the confocal scanning microscope with open and annular apertures, are presented. It was shown that the confocal scanning microscope opens indeed new opportunities for the nuclear photoemulsion technique to get previously inaccessible information for physics of the short-living particles

  14. Apoptosis study of the macrophage via near-field scanning optical microscope

    International Nuclear Information System (INIS)

    Wang, D-C; Chen, K-Y; Chen, G-Y; Chen, S-H; Wun, S-J

    2008-01-01

    The cell apoptosis phenomenon was studied by traditional optical microscope with much lower resolution and also observed by Atomic Force Microscope (AFM) with nano-resolution recently. They both detect the cell apoptosis through the change of cell topography. In this study, the cell apoptosis was investigated via Near-Field Scanning Optical Microscope (NSOM). The cell topography, with nano-scaled resolution, and its optical characteristics were observed by NSOM at the same measurement scanning. The macrophage was chosen as the cell investigated. To understand the cell apoptosis process is the goal set for the research. The apoptosis process was related to the variations of the optical characteristics of the cell

  15. Nitrogen implantation with a scanning electron microscope.

    Science.gov (United States)

    Becker, S; Raatz, N; Jankuhn, St; John, R; Meijer, J

    2018-01-08

    Established techniques for ion implantation rely on technically advanced and costly machines like particle accelerators that only few research groups possess. We report here about a new and surprisingly simple ion implantation method that is based upon a widespread laboratory instrument: The scanning electron microscope. We show that it can be utilized to ionize atoms and molecules from the restgas by collisions with electrons of the beam and subsequently accelerate and implant them into an insulating sample by the effect of a potential building up at the sample surface. Our method is demonstrated by the implantation of nitrogen ions into diamond and their subsequent conversion to nitrogen vacancy centres which can be easily measured by fluorescence confocal microscopy. To provide evidence that the observed centres are truly generated in the way we describe, we supplied a 98% isotopically enriched 15 N gas to the chamber, whose natural abundance is very low. By employing the method of optically detected magnetic resonance, we were thus able to verify that the investigated centres are actually created from the 15 N isotopes. We also show that this method is compatible with lithography techniques using e-beam resist, as demonstrated by the implantation of lines using PMMA.

  16. phytochemical and microscopical evaluation of desmodium velutinum

    African Journals Online (AJOL)

    USER

    2015-06-01

    , transverse and longitudinal sections of the leaves of .... quantity for preliminary screening and biological studies. Microscopical Examination .... subnitrate dissolved in 20ml acetic acid, made up to 100ml with distilled water).

  17. Feedback regulation of microscopes by image processing.

    Science.gov (United States)

    Tsukada, Yuki; Hashimoto, Koichi

    2013-05-01

    Computational microscope systems are becoming a major part of imaging biological phenomena, and the development of such systems requires the design of automated regulation of microscopes. An important aspect of automated regulation is feedback regulation, which is the focus of this review. As modern microscope systems become more complex, often with many independent components that must work together, computer control is inevitable since the exact orchestration of parameters and timings for these multiple components is critical to acquire proper images. A number of techniques have been developed for biological imaging to accomplish this. Here, we summarize the basics of computational microscopy for the purpose of building automatically regulated microscopes focus on feedback regulation by image processing. These techniques allow high throughput data acquisition while monitoring both short- and long-term dynamic phenomena, which cannot be achieved without an automated system. © 2013 The Authors Development, Growth & Differentiation © 2013 Japanese Society of Developmental Biologists.

  18. Assessing and benchmarking multiphoton microscopes for biologists.

    Science.gov (United States)

    Corbin, Kaitlin; Pinkard, Henry; Peck, Sebastian; Beemiller, Peter; Krummel, Matthew F

    2014-01-01

    Multiphoton microscopy has become staple tool for tracking cells within tissues and organs due to superior depth of penetration, low excitation volumes, and reduced phototoxicity. Many factors, ranging from laser pulse width to relay optics to detectors and electronics, contribute to the overall ability of these microscopes to excite and detect fluorescence deep within tissues. However, we have found that there are few standard ways already described in the literature to distinguish between microscopes or to benchmark existing microscopes to measure the overall quality and efficiency of these instruments. Here, we discuss some simple parameters and methods that can either be used within a multiphoton facility or by a prospective purchaser to benchmark performance. This can both assist in identifying decay in microscope performance and in choosing features of a scope that are suited to experimental needs. © 2014 Elsevier Inc. All rights reserved.

  19. Nucleon relativistic phenomenological and microscopic optical potential

    International Nuclear Information System (INIS)

    Shen Qingbiao; Feng Dachun; Zhuo Yizhong

    1991-01-01

    In this talk, both the phenomenological and microscopic nucleon relativistic optical potentials are presented. The global neutron relativistic phenomenological optical potential (RPOP) based on the available experimental data for various nuclei ranging from C to U with incident energies En=20-1000 MeV has been obtained through automatic search of the best parameters by computer. Then the nucleon relativistic microscopic optical potential (RMOP) is studied by utilizing effective lagrangian based on popular Walecka model. Through comparison between the theoretical results and experimental data we have shed some insight into both the RMOP and RPOP. We have concluded that both the phenomenological and microscopic relativistic optical potentials proposed here can be extensively used for intermediate energy nucleon data evaluation. Further improvement concerning how to combine the phenomenological potential with the microscopic one in order to reduce the number of free parameters appearing in RPOP is suggested. (author). 33 refs, 24 figs

  20. Understanding and caring for an operating microscope

    Directory of Open Access Journals (Sweden)

    Ismael Cordero

    2014-04-01

    Full Text Available An operating or surgical microscope is an optical instrument that provides the surgeon with a stereoscopic, high quality magnified and illuminated image of the small structures in the surgical area.

  1. Assessing and benchmarking multiphoton microscopes for biologists

    Science.gov (United States)

    Corbin, Kaitlin; Pinkard, Henry; Peck, Sebastian; Beemiller, Peter; Krummel, Matthew F.

    2017-01-01

    Multiphoton microscopy has become staple tool for tracking cells within tissues and organs due to superior depth of penetration, low excitation volumes, and reduced phototoxicity. Many factors, ranging from laser pulse width to relay optics to detectors and electronics, contribute to the overall ability of these microscopes to excite and detect fluorescence deep within tissues. However, we have found that there are few standard ways already described in the literature to distinguish between microscopes or to benchmark existing microscopes to measure the overall quality and efficiency of these instruments. Here, we discuss some simple parameters and methods that can either be used within a multiphoton facility or by a prospective purchaser to benchmark performance. This can both assist in identifying decay in microscope performance and in choosing features of a scope that are suited to experimental needs. PMID:24974026

  2. A pragmatic guide to multiphoton microscope design

    Science.gov (United States)

    Young, Michael D.; Field, Jeffrey J.; Sheetz, Kraig E.; Bartels, Randy A.; Squier, Jeff

    2016-01-01

    Multiphoton microscopy has emerged as a ubiquitous tool for studying microscopic structure and function across a broad range of disciplines. As such, the intent of this paper is to present a comprehensive resource for the construction and performance evaluation of a multiphoton microscope that will be understandable to the broad range of scientific fields that presently exploit, or wish to begin exploiting, this powerful technology. With this in mind, we have developed a guide to aid in the design of a multiphoton microscope. We discuss source selection, optical management of dispersion, image-relay systems with scan optics, objective-lens selection, single-element light-collection theory, photon-counting detection, image rendering, and finally, an illustrated guide for building an example microscope. PMID:27182429

  3. X ray imaging microscope for cancer research

    Science.gov (United States)

    Hoover, Richard B.; Shealy, David L.; Brinkley, B. R.; Baker, Phillip C.; Barbee, Troy W., Jr.; Walker, Arthur B. C., Jr.

    1991-01-01

    The NASA technology employed during the Stanford MSFC LLNL Rocket X Ray Spectroheliograph flight established that doubly reflecting, normal incidence multilayer optics can be designed, fabricated, and used for high resolution x ray imaging of the Sun. Technology developed as part of the MSFC X Ray Microscope program, showed that high quality, high resolution multilayer x ray imaging microscopes are feasible. Using technology developed at Stanford University and at the DOE Lawrence Livermore National Laboratory (LLNL), Troy W. Barbee, Jr. has fabricated multilayer coatings with near theoretical reflectivities and perfect bandpass matching for a new rocket borne solar observatory, the Multi-Spectral Solar Telescope Array (MSSTA). Advanced Flow Polishing has provided multilayer mirror substrates with sub-angstrom (rms) smoothnesss for the astronomical x ray telescopes and x ray microscopes. The combination of these important technological advancements has paved the way for the development of a Water Window Imaging X Ray Microscope for cancer research.

  4. A lensless, automated microscope for disease diagnostics

    CSIR Research Space (South Africa)

    Hugo, S

    2012-03-01

    Full Text Available using a conventional bright field microscope. Applications of this work are targeted towards the implementation of a full blood count, which could provide resource-limited areas with improved healthcare facilities and diagnosis times....

  5. A lensless, automated microscope for disease diagnostics

    CSIR Research Space (South Africa)

    Hugo, S

    2011-09-01

    Full Text Available microscope. Applications of this work are targeted towards the implementation of a full blood count, which could provide resource-limited areas with improved healthcare facilities and diagnosis times....

  6. Optics of high-performance electron microscopes*

    OpenAIRE

    Rose, H H

    2016-01-01

    During recent years, the theory of charged particle optics together with advances in fabrication tolerances and experimental techniques has lead to very significant advances in high-performance electron microscopes. Here, we will describe which theoretical tools, inventions and designs have driven this development. We cover the basic theory of higher-order electron optics and of image formation in electron microscopes. This leads to a description of different methods to correct aberrations by...

  7. [The Development of First Operating Microscopes from Zeiss Jena and Oberkochen to Series Production].

    Science.gov (United States)

    Gudziol, H; Gottschall, R; Luther, E

    2017-01-01

    Introduction: The history of the first operating microscopes from Zeiss is often confusing, not painstaking and partly contradictory because of the parallel development of Zeiss Jena (East Germany) and Zeiss Oberkochen (West Germany). Methods: To investigate the early beginnings of the construction of the operating microscopes documents of the Carl Zeiss Archive and the Optical Museum in Jena, the memoirs of Prof. Dr. Rosemarie Albrecht and some relevant publications were used. Results: The development of the first Jena operating microscope was initiated in 1949 by the ENT-physician Prof. Dr. Rosemarie Albrecht in the Soviet occupation zone. The first prototype was tested in the University ENT Clinic, Jena since summer of 1950. On the Leipzig Trade Fair in autumn 1952 the VEB Optik Carl Zeiss Jena presented the first operating microscope nationally and internationally. Series production began in 1953. The first operating microscope of Zeiss Oberkochen was primarily developed by technical designers (H. Littmann) as a colposcope. But in the Carl Zeiss Archive no documents could be found related to the cooperation with gynecologists. 1953 the operating microscope (OPMI 1) came into public and its series production started. From this date on, it was adopted by the otologist Prof. Dr. Horst Ludwig Wullstein to the needs of Otorhinolaryngology. Conclusion: The first Zeiss operating microscope came from Jena. The operating microscope from Zeiss Oberkochen had some advantages for the surgeons and won the competition in the future. © Georg Thieme Verlag KG Stuttgart · New York.

  8. Influence of microscopic heterogeneity on diffusion for sedimentary rocks

    International Nuclear Information System (INIS)

    Ota, K.; Yoshida, H.

    1995-01-01

    To build confidence in radionuclide migration models for the performance assessment of geological disposal system of high-level radioactive waste, the limitation of applicability of a diffusion model for sedimentary rocks, has been tested by combination of field observations and relevant laboratory experiments. Comparison of the data between the field observations and an in-diffusion experiment with uranium solution have been carried out. The results of the combination work indicate that microscopic heterogeneity of the flow-path geometry and the distribution of constituent minerals should be taken into account for the further model development. Investigations on the effects of microscopic heterogeneity of rock fabrics must therefore be conducted. (authors). 10 refs., 4 figs., 1 tab

  9. Nanometer-scale lithography on microscopically clean graphene

    DEFF Research Database (Denmark)

    van Dorp, W. F.; Zhang, X.; Feringa, B. L.

    2011-01-01

    Focused-electron-beam-induced deposition, or FEBID, enables the fabrication of patterns with sub-10 nm resolution. The initial stages of metal deposition by FEBID are still not fundamentally well understood. For these investigations, graphene, a one-atom-thick sheet of carbon atoms in a hexagonal...... lattice, is ideal as the substrate for FEBID writing. In this paper, we have used exfoliated few-layer graphene as a support to study the early growth phase of focused-electron-beam-induced deposition and to write patterns with dimensions between 0.6 and 5 nm. The results obtained here are compared...... to the deposition behavior on amorphous materials. Prior to the deposition experiment, the few-layer graphene was cleaned. Typically, it is observed in electron microscope images that areas of microscopically clean graphene are surrounded by areas with amorphous material. We present a method to remove the amorphous...

  10. Muon spin rotation and other microscopic probes of spin-glass dynamics

    International Nuclear Information System (INIS)

    MacLaughlin, D.E.

    1980-01-01

    A number of different microscopic probe techniques have been employed to investigate the onset of the spin-glass state in dilute magnetic alloys. Among these are Moessbauer-effect spectroscopy, neutron scattering, ESR of the impurity spins, host NMR and, most recently, muon spin rotation and depolarization. Spin probes yield information on the microscopic static and dynamic behavior of the impurity spins, and give insight into both the spin freezing process and the nature of low-lying excitations in the ordered state. Microscopic probe experiments in spin glasses are surveyed, and the unique advantages of muon studies are emphasized

  11. Postirradiation changes in rat brain. Observations in light- and scanning microscope

    International Nuclear Information System (INIS)

    Kiczka-Wojczuk, J.; Sosnierz, M.; Bialas, B.; Wazna-Bogunska, C.

    1977-01-01

    Irradiation changes in central nervous system of the rat were evaluated. Fifty rats irradiated by a single dose of 1000 R were used. A special attention was paid to changes in ventricular ependyma. The changes observed in scanning microscope consisted of loss of cilia, swelling of ependymal cells and changes in their nuclear profiles. The changes presented in light microscope were typical for postirradiation damage of the brain. The authors express the opinion that scanning microscope offers a valuable, complementary tool for routine neuropathological investigations. (author)

  12. Caustic meso-optical confocal microscope for vertical particle tracks. Proposal

    International Nuclear Information System (INIS)

    Soroko, L.M.

    1995-01-01

    The principal of the proposed caustic meso-optical microscope for vertical particle tracks in the nuclear photoemulsion is explained. The results of the experiments performed to illustrate the main features of this new meso-optical microscope are given. The proposed caustic meso-optical microscope for vertical particle tracks in the nuclear photoemulsion can be effectively used in the experimental investigation of such rare processes as ν μ - ν τ oscillations and of the Pb-Pb interactions. 2 refs., 7 figs

  13. Numerical restoration of surface vortices in Nb films measured by a scanning SQUID microscope

    Science.gov (United States)

    Ito, Atsuki; Thanh Huy, Ho; Dang, Vu The; Miyoshi, Hiroki; Hayashi, Masahiko; Ishida, Takekazu

    2017-07-01

    In the present work, we investigated a vortex profile appeared on a pure Nb film (500 nm in thickness, 10 mm x 10 mm) by using a scanning SQUID microscope. We found that the local magnetic distribution thus observed is broadened compared to a true vortex profile in the superconducting film. We therefore applied the numerical method to improve a spatial resolution of the scanning SQUID microscope. The method is based on the inverse Biot-Savart law and the Fourier transformation to recover a real-space image. We found that the numerical analyses give a smaller vortex than the raw vortex profile observed by the scanning microscope.

  14. Miniaturized integration of a fluorescence microscope

    Science.gov (United States)

    Ghosh, Kunal K.; Burns, Laurie D.; Cocker, Eric D.; Nimmerjahn, Axel; Ziv, Yaniv; Gamal, Abbas El; Schnitzer, Mark J.

    2013-01-01

    The light microscope is traditionally an instrument of substantial size and expense. Its miniaturized integration would enable many new applications based on mass-producible, tiny microscopes. Key prospective usages include brain imaging in behaving animals towards relating cellular dynamics to animal behavior. Here we introduce a miniature (1.9 g) integrated fluorescence microscope made from mass-producible parts, including semiconductor light source and sensor. This device enables high-speed cellular-level imaging across ∼0.5 mm2 areas in active mice. This capability allowed concurrent tracking of Ca2+ spiking in >200 Purkinje neurons across nine cerebellar microzones. During mouse locomotion, individual microzones exhibited large-scale, synchronized Ca2+ spiking. This is a mesoscopic neural dynamic missed by prior techniques for studying the brain at other length scales. Overall, the integrated microscope is a potentially transformative technology that permits distribution to many animals and enables diverse usages, such as portable diagnostics or microscope arrays for large-scale screens. PMID:21909102

  15. Optical alignment using the Point Source Microscope

    Science.gov (United States)

    Parks, Robert E.; Kuhn, William P.

    2005-08-01

    We give an example of a Point Source Microscope (PSM) and describe its uses as an aid in the alignment of optical systems including the referencing of optical to mechanical datums. The PSM is a small package (about 100x150x30 mm), including a point source of light, beam splitter, microscope objective and digital CCD camera to detect the reflected light spot. A software package in conjunction with a computer video display locates the return image in three degrees of freedom relative to an electronic spatial reference point. The PSM also includes a Koehler illumination source so it may be used as a portable microscope for ordinary imaging and the microscope can be zoomed under computer control. For added convenience, the laser diode point source can be made quite bright to facilitate initial alignment under typical laboratory lighting conditions. The PSM is particularly useful in aligning optical systems that do not have circular symmetry or are distributed in space such as off-axis systems. The PSM is also useful for referencing the centers of curvatures of optical surfaces to mechanical datums of the structure in which the optics are mounted. By removing the microscope objective the PSM can be used as an electronic autocollimator because of the infinite conjugate optical design.

  16. A frameless stereotaxic operating microscope for neurosurgery

    International Nuclear Information System (INIS)

    Friets, E.M.; Strohbehn, J.W.; Hatch, J.F.; Roberts, D.W.

    1989-01-01

    A new system, which we call the frameless stereotaxic operating microscope, is discussed. Its purpose is to display CT or other image data in the operating microscope in the correct scale, orientation, and position without the use of a stereotaxic frame. A nonimaging ultrasonic rangefinder allows the position of the operating microscope and the position of the patient to be determined. Discrete fiducial points on the patient's external anatomy are located in both image space and operating room space, linking the image data and the operating room. Physician-selected image information, e.g., tumor contours or guidance to predetermined targets, is projected through the optics of the operating microscope using a miniature cathode ray tube and a beam splitter. Projected images superpose the surgical field, reconstructed from image data to match the focal plane of the operating microscope. The algorithms on which the system is based are described, and the sources and effects of errors are discussed. The system's performance is simulated, providing an estimate of accuracy. Two phantoms are used to measure accuracy experimentally. Clinical results and observations are given

  17. The optics of microscope image formation.

    Science.gov (United States)

    Wolf, David E

    2013-01-01

    Although geometric optics gives a good understanding of how the microscope works, it fails in one critical area, which is explaining the origin of microscope resolution. To accomplish this, one must consider the microscope from the viewpoint of physical optics. This chapter describes the theory of the microscope-relating resolution to the highest spatial frequency that a microscope can collect. The chapter illustrates how Huygens' principle or construction can be used to explain the propagation of a plane wave. It is shown that this limit increases with increasing numerical aperture (NA). As a corollary to this, resolution increases with decreasing wavelength because of how NA depends on wavelength. The resolution is higher for blue light than red light. Resolution is dependent on contrast, and the higher the contrast, the higher the resolution. This last point relates to issues of signal-to-noise and dynamic range. The use of video and new digital cameras has necessitated redefining classical limits such as those of Rayleigh's criterion. Copyright © 2007 Elsevier Inc. All rights reserved.

  18. Microscopic Characterization of Scalable Coherent Rydberg Superatoms

    Science.gov (United States)

    Zeiher, Johannes; Schauß, Peter; Hild, Sebastian; Macrı, Tommaso; Bloch, Immanuel; Gross, Christian

    2015-07-01

    Strong interactions can amplify quantum effects such that they become important on macroscopic scales. Controlling these coherently on a single-particle level is essential for the tailored preparation of strongly correlated quantum systems and opens up new prospects for quantum technologies. Rydberg atoms offer such strong interactions, which lead to extreme nonlinearities in laser-coupled atomic ensembles. As a result, multiple excitation of a micrometer-sized cloud can be blocked while the light-matter coupling becomes collectively enhanced. The resulting two-level system, often called a "superatom," is a valuable resource for quantum information, providing a collective qubit. Here, we report on the preparation of 2 orders of magnitude scalable superatoms utilizing the large interaction strength provided by Rydberg atoms combined with precise control of an ensemble of ultracold atoms in an optical lattice. The latter is achieved with sub-shot-noise precision by local manipulation of a two-dimensional Mott insulator. We microscopically confirm the superatom picture by in situ detection of the Rydberg excitations and observe the characteristic square-root scaling of the optical coupling with the number of atoms. Enabled by the full control over the atomic sample, including the motional degrees of freedom, we infer the overlap of the produced many-body state with a W state from the observed Rabi oscillations and deduce the presence of entanglement. Finally, we investigate the breakdown of the superatom picture when two Rydberg excitations are present in the system, which leads to dephasing and a loss of coherence.

  19. Microscopic Characterization of Scalable Coherent Rydberg Superatoms

    Directory of Open Access Journals (Sweden)

    Johannes Zeiher

    2015-08-01

    Full Text Available Strong interactions can amplify quantum effects such that they become important on macroscopic scales. Controlling these coherently on a single-particle level is essential for the tailored preparation of strongly correlated quantum systems and opens up new prospects for quantum technologies. Rydberg atoms offer such strong interactions, which lead to extreme nonlinearities in laser-coupled atomic ensembles. As a result, multiple excitation of a micrometer-sized cloud can be blocked while the light-matter coupling becomes collectively enhanced. The resulting two-level system, often called a “superatom,” is a valuable resource for quantum information, providing a collective qubit. Here, we report on the preparation of 2 orders of magnitude scalable superatoms utilizing the large interaction strength provided by Rydberg atoms combined with precise control of an ensemble of ultracold atoms in an optical lattice. The latter is achieved with sub-shot-noise precision by local manipulation of a two-dimensional Mott insulator. We microscopically confirm the superatom picture by in situ detection of the Rydberg excitations and observe the characteristic square-root scaling of the optical coupling with the number of atoms. Enabled by the full control over the atomic sample, including the motional degrees of freedom, we infer the overlap of the produced many-body state with a W state from the observed Rabi oscillations and deduce the presence of entanglement. Finally, we investigate the breakdown of the superatom picture when two Rydberg excitations are present in the system, which leads to dephasing and a loss of coherence.

  20. Macroscopic and microscopic assessments of the glenohumeral and subacromial synovitis in rotator cuff disease.

    Science.gov (United States)

    Jo, Chris H; Shin, Ji Sun; Kim, Ji Eun; Oh, Sohee

    2015-09-30

    Whereas synovitis is one of most common findings during arthroscopic surgery in patients with rotator cuff diseases, no study has investigated its characteristics. We propose a macroscopic assessment system for investigating the characteristics of synovitis. Fifty-four patients with a full-thickness rotator cuff tear undergoing arthroscopic rotator cuff repair with an average age of 62.5 ± 7.0 years were included. For the macroscopic assessment, 3 parameters, villous hypertrophy, hyperemia, and density, were measured and translated into grades in 3 regions-of-interest (ROI) in the glenohumeral joint and 4 ROIs in the subacromial space. For the microscopic assessments, 4 commonly used microscopic assessment systems were used. The reliability and association between the macroscopic and microscopic assessments were investigated. The inter- and intra-observer reliability of all of the macroscopic and microscopic assessments were excellent. The severity of synovitis was significantly greater in the glenohumeral joint than that in the subacromial space, 1.54 ± 0.61 versus 0.94 ± 0.56 (p system. Meanwhile, none of the microscopic assessment systems demonstrated differences between different ROIs in both the glenohumeral joint and the subacromial space. The macroscopic assessment system for synovitis in rotator cuff disease in this study showed excellent reliability. It critically described characteristics of synovitis that microscopic assessment systems could not. Therefore, this system could be a useful tool for investigating synovitis in rotator cuff disease.

  1. Transcanal microscope-assisted endoscopic myringoplasty in children.

    Science.gov (United States)

    Migirov, Lela; Wolf, Michael

    2015-04-01

    Myringoplasty can be technically difficult in the pediatric patients due to the narrowness of the external auditory canal and the generally small size of the ear. Moreover, temporalis fascia grafts and myringoplasties for anterior perforations are more likely to fail in children. Surgical management of anterior perforations requires total exposure of the anterior angle however a microscope may fail to provide a view of the anterior edge in most of perforations. Recently, different endoscopes are used in the performance of ear surgery in general and myringoplasty in particular. Current study aimed to investigate the outcome of transcanal microscope-assisted endoscopic myringoplasty in homogenous group of children. The medical records of 22 children were retrospectively reviewed for age, perforation size and location, surgical and audiological findings, and outcome. All myringoplasties were performed by first author with a chondro-perichondrial graft that has been harvested from the tragus and placed medial to the tympanic membrane remnants, utilizing the underlay technique and 14-mm length, 3-mm diameter, 0° and 30° endoscopes. A microscope was occasionally used for removal of the sclerotic plaques and releasing adhesions surrounding the ossicles when bimanual manipulations were needed. Surgical success was defined as a tympanic membrane with no perforation, retraction, or graft lateralization for at least 18 months following surgery. Thirteen large-, 8 medium- and 1 small-sized perforations (defined as 75, 50 or 25%, respectively, of the tympanic membrane area), of which 14 were anterior, 2 central and 6 posterior marginal, were repaired. The edges of the defect could not be visualized under a microscope due to bone overhanging or a curved or narrow EAC in 8 anterior perforations. Intact tympanic membranes and dry ears were achieved in all operated children. The audiometric air conduction level (average of 0.5-3 kHz) for the entire cohort ranged between 10-51.3 d

  2. Determination of the parameters of a microscopic object from a complex response of a differential microscope

    International Nuclear Information System (INIS)

    Baranov, D V; Egorov, Alexander A; Zolotov, Evgenii M; Svidzinsky, K K

    1998-01-01

    An analysis of the amplitude and phase of a complex response of a heterodyne differential microscope was used to demonstrate experimentally the feasibility of determination of the parameters of a composite microscopic object representing a combination of a step with a groove. (laser applications and other topics in quantum electronics)

  3. HANDY MICROSCOPIC CLOSE-RANGE VIDEOGRAMMETRY

    Directory of Open Access Journals (Sweden)

    F. Esmaeili

    2017-09-01

    Full Text Available The modeling of small-scale objects is used in different applications such as medicine, industry, and cultural heritage. The capability of modeling small-scale objects using imaging with the help of hand USB digital microscopes and use of videogrammetry techniques has been implemented and evaluated in this paper. Use of this equipment and convergent imaging of the environment for modeling, provides an appropriate set of images for generation of three-dimensional models. The results of the measurements made with the help of a microscope micrometer calibration ruler have demonstrated that self-calibration of a hand camera-microscope set can help obtain a three-dimensional detail extraction precision of about 0.1 millimeters on small-scale environments.

  4. Environmental TEM in an Aberration Corrected Microscope

    DEFF Research Database (Denmark)

    Hansen, Thomas Willum; Wagner, Jakob Birkedal

    ‐resolution imaging. A gaseous atmosphere in the pole‐piece gap of the objective lens of the microscope alters both the incoming electron wave prior to interaction with the sample and the outgoing wave below the sample. Whereas conventional TEM samples are usually thin (below 10‐20 nm), the gas in the environmental...... the microscope column. The effects of gas on the electron wave in the objective lens are not well understood and needs further attention. Imaging samples with a simple geometry, such as gold particles on a flat graphene substrate and analyzing the variations in contrast, provides a means for understanding...... results from imaging in various elemental as well as di‐molecular gases and their effect on imaging and spectroscopy in the environmental transmission electron microscope....

  5. Scanning probe microscope dimensional metrology at NIST

    International Nuclear Information System (INIS)

    Kramar, John A; Dixson, Ronald; Orji, Ndubuisi G

    2011-01-01

    Scanning probe microscope (SPM) dimensional metrology efforts at the US National Institute of Standards and Technology (NIST) are reviewed in this paper. The main SPM instruments for realizing the International System of Units (SI) are the Molecular Measuring Machine, the calibrated atomic force microscope and the critical dimension atomic force microscope. These are optimized for long-distance measurements, three-dimensional measurements over conventional SPM distances and critical dimension or linewidth measurements, respectively. 10 mm distances have been measured with the relative standard uncertainty, u c , of 1.5 × 10 −5 ; step heights at the 100 nm scale have been measured with the relative u c of 2.5 × 10 −3 and sub-micrometer linewidths have been measured with u c = 0.8 nm

  6. Neutron relativistic phenomenological and microscopic optical potential

    International Nuclear Information System (INIS)

    Shen Qing-biao; Feng Da-chun; Zhuo Yi-zhong

    1991-01-01

    In this paper, both the phenomenological and microscopic neutron relativistic optical potentials are presented. The global neutron relativistic phenomenological optical potential (RPOP) based on the available experimental data for various nuclei ranging from C to U with incident energies E n =20--1000 MeV has been obtained through an automatic search of the best parameters by computer. Then the nucleon relativistic microscopic optical potential (RMOP) is studied by utilizing the effective Lagrangian based on the popular Walecka model. Through comparison between the theoretical results and experimental data we shed some insight into both the RMOP and RPOP. Further improvement concerning how to combine the phenomenological potential with the microscopic one in order to reduce the number of free parameters appearing in the RPOP is suggested

  7. CHAMP - Camera, Handlens, and Microscope Probe

    Science.gov (United States)

    Mungas, G. S.; Beegle, L. W.; Boynton, J.; Sepulveda, C. A.; Balzer, M. A.; Sobel, H. R.; Fisher, T. A.; Deans, M.; Lee, P.

    2005-01-01

    CHAMP (Camera, Handlens And Microscope Probe) is a novel field microscope capable of color imaging with continuously variable spatial resolution from infinity imaging down to diffraction-limited microscopy (3 micron/pixel). As an arm-mounted imager, CHAMP supports stereo-imaging with variable baselines, can continuously image targets at an increasing magnification during an arm approach, can provide precision range-finding estimates to targets, and can accommodate microscopic imaging of rough surfaces through a image filtering process called z-stacking. Currently designed with a filter wheel with 4 different filters, so that color and black and white images can be obtained over the entire Field-of-View, future designs will increase the number of filter positions to include 8 different filters. Finally, CHAMP incorporates controlled white and UV illumination so that images can be obtained regardless of sun position, and any potential fluorescent species can be identified so the most astrobiologically interesting samples can be identified.

  8. Compact Microscope Imaging System with Intelligent Controls

    Science.gov (United States)

    McDowell, Mark

    2004-01-01

    The figure presents selected views of a compact microscope imaging system (CMIS) that includes a miniature video microscope, a Cartesian robot (a computer- controlled three-dimensional translation stage), and machine-vision and control subsystems. The CMIS was built from commercial off-the-shelf instrumentation, computer hardware and software, and custom machine-vision software. The machine-vision and control subsystems include adaptive neural networks that afford a measure of artificial intelligence. The CMIS can perform several automated tasks with accuracy and repeatability . tasks that, heretofore, have required the full attention of human technicians using relatively bulky conventional microscopes. In addition, the automation and control capabilities of the system inherently include a capability for remote control. Unlike human technicians, the CMIS is not at risk of becoming fatigued or distracted: theoretically, it can perform continuously at the level of the best human technicians. In its capabilities for remote control and for relieving human technicians of tedious routine tasks, the CMIS is expected to be especially useful in biomedical research, materials science, inspection of parts on industrial production lines, and space science. The CMIS can automatically focus on and scan a microscope sample, find areas of interest, record the resulting images, and analyze images from multiple samples simultaneously. Automatic focusing is an iterative process: The translation stage is used to move the microscope along its optical axis in a succession of coarse, medium, and fine steps. A fast Fourier transform (FFT) of the image is computed at each step, and the FFT is analyzed for its spatial-frequency content. The microscope position that results in the greatest dispersal of FFT content toward high spatial frequencies (indicating that the image shows the greatest amount of detail) is deemed to be the focal position.

  9. Development of Near-Field Microwave Microscope with the Functionality of Scanning Tunneling Spectroscopy

    Science.gov (United States)

    Machida, Tadashi; Gaifullin, Marat B.; Ooi, Shuuich; Kato, Takuya; Sakata, Hideaki; Hirata, Kazuto

    2010-11-01

    We describe the details of an original near-field scanning microwave microscope, developed for simultaneous measurements of local density-of-states (LDOS) and local ohmic losses (LOL). Improving microwave detection systems, we have succeeded in distinguishing the LDOS and LOL even between two low resistance materials; gold and highly orientated pyrolitic graphite. The experimental data indicate that our microscope holds a capability to investigate both LDOS and LOL in nanoscale.

  10. Transmission electron microscope studies of crystalline LiNbO3

    International Nuclear Information System (INIS)

    Pareja, R.; Gonzalez, R.; Chen, Y.

    1984-01-01

    Transmission electron microscope investigations in both as-grown and hydrogen-reduced LiNbO 3 reveal that niobium oxide precipitates can be produced by in situ irradiations in the electron microscope. The precipitation process is produced by a combined effect of ionizing electrons and the thermal heating of the specimens during irradiation. It is proposed that the composition of the precipitates is primarily Nb 2 O 5

  11. Phase zone plate based scanning x-ray microscope

    International Nuclear Information System (INIS)

    Legnini, D.; Yun, W.; Lai, B.; Chrzas, J.

    1992-01-01

    A scanning microscope capable of investigating materials in the x-ray region from 5-25 keV with a spatial resolution on the order of 1 μm has been constructed and experimentally demonstrated. A phase zone plate is used as a focusing element concentrating photons at a series of diffraction orders spaced along the optical axis. A sample is positioned at one of these focal planes and raster scanned across the small focal spot for imaging or micro-analysis. Use and characterization of the microscope requires precise alignment of the zone plate and its optical axis along the x-ray beam direction. Also needed are accurate, reproducible positioning of an order selection aperture and sample. Operation at different focal orders involves large translations of sample and aperture along the optical axis as well as adjustment of the aperture to sample distance. A motion control, data acquisition, and display system has been developed to meet these requirements of sample and detector positioning. Design considerations and results obtained from use of the microscope for imaging at first through fourth order focal planes are discussed

  12. Single-channel stereoscopic ophthalmology microscope based on TRD

    Science.gov (United States)

    Radfar, Edalat; Park, Jihoon; Lee, Sangyeob; Ha, Myungjin; Yu, Sungkon; Jang, Seulki; Jung, Byungjo

    2016-03-01

    A stereoscopic imaging modality was developed for the application of ophthalmology surgical microscopes. A previous study has already introduced a single-channel stereoscopic video imaging modality based on a transparent rotating deflector (SSVIM-TRD), in which two different view angles, image disparity, are generated by imaging through a transparent rotating deflector (TRD) mounted on a stepping motor and is placed in a lens system. In this case, the image disparity is a function of the refractive index and the rotation angle of TRD. Real-time single-channel stereoscopic ophthalmology microscope (SSOM) based on the TRD is improved by real-time controlling and programming, imaging speed, and illumination method. Image quality assessments were performed to investigate images quality and stability during the TRD operation. Results presented little significant difference in image quality in terms of stability of structural similarity (SSIM). A subjective analysis was performed with 15 blinded observers to evaluate the depth perception improvement and presented significant improvement in the depth perception capability. Along with all evaluation results, preliminary results of rabbit eye imaging presented that the SSOM could be utilized as an ophthalmic operating microscopes to overcome some of the limitations of conventional ones.

  13. Cleft Lip and Palate Repair Using a Surgical Microscope.

    Science.gov (United States)

    Kato, Motoi; Watanabe, Azusa; Watanabe, Shoji; Utsunomiya, Hiroki; Yokoyama, Takayuki; Ogishima, Shinya

    2017-11-01

    Cleft lip and palate repair requires a deep and small surgical field and is usually performed by surgeons wearing surgical loupes. Surgeons with loupes can obtain a wider surgical view, although headlights are required for the deepest procedures. Surgical microscopes offer comfort and a clear and magnification-adjustable surgical site that can be shared with the whole team, including observers, and easily recorded to further the education of junior surgeons. Magnification adjustments are convenient for precise procedures such as muscle dissection of the soft palate. We performed a comparative investigation of 18 cleft operations that utilized either surgical loupes or microscopy. Paper-based questionnaires were completed by staff nurses to evaluate what went well and what could be improved in each procedure. The operating time, complication rate, and scores of the questionnaire responses were statistically analyzed. The operating time when microscopy was used was not significantly longer than when surgical loupes were utilized. The surgical field was clearly shared with surgical assistants, nurses, anesthesiologists, and students via microscope-linked monitors. Passing surgical equipment was easier when sharing the surgical view, and preoperative microscope preparation did not interfere with the duties of the staff nurses. Surgical microscopy was demonstrated to be useful during cleft operations.

  14. Nanometer-scale lithography on microscopically clean graphene

    International Nuclear Information System (INIS)

    Van Dorp, W F; De Hosson, J Th M; Zhang, X; Feringa, B L; Wagner, J B; Hansen, T W

    2011-01-01

    Focused-electron-beam-induced deposition, or FEBID, enables the fabrication of patterns with sub-10 nm resolution. The initial stages of metal deposition by FEBID are still not fundamentally well understood. For these investigations, graphene, a one-atom-thick sheet of carbon atoms in a hexagonal lattice, is ideal as the substrate for FEBID writing. In this paper, we have used exfoliated few-layer graphene as a support to study the early growth phase of focused-electron-beam-induced deposition and to write patterns with dimensions between 0.6 and 5 nm. The results obtained here are compared to the deposition behavior on amorphous materials. Prior to the deposition experiment, the few-layer graphene was cleaned. Typically, it is observed in electron microscope images that areas of microscopically clean graphene are surrounded by areas with amorphous material. We present a method to remove the amorphous material in order to obtain large areas of microscopically clean graphene flakes. After cleaning, W(CO) 6 was used as the precursor to study the early growth phase of FEBID deposits. It was observed that preferential adsorption of the precursor molecules on step edges and adsorbates plays a key role in the deposition on cleaned few-layer graphene.

  15. The microscopic structure of the hydrogen liquids

    CERN Document Server

    Zoppi, M; Celli, M; Cuello, G J; Formisano, F; Guarini, E; Magli, R; Neumann, M

    2003-01-01

    We have measured the microscopic structure of liquid para-hydrogen by means of a neutron diffraction experiment on the D4C liquids diffractometer at Institute Laue-Langevin (Grenoble, France). This is the first direct neutron diffraction measurement of the static structure factor of hydrogen. The present determination of the microscopic structure of hydrogen is consistent with previous experimental determinations carried out on liquid deuterium and with path integral Monte Carlo simulations. The comparison with recent x-ray determinations is also satisfactory.

  16. Optofluidic microscope with 3D spatial resolution

    DEFF Research Database (Denmark)

    Vig, Asger Laurberg; Marie, Rodolphe; Jensen, Eric

    2010-01-01

    This paper reports on-chip based optical detection with three-dimensional spatial resolution by integration of an optofluidic microscope (OFM) in a microfluidic pinched flow fractionation (PFF) separation device. This setup also enables on-chip particle image velocimetry (PIV). The position...... fluorescence microscope readout. The size separated microspheres are detected by OFM with an accuracy of ≤0.92μm. The position in the height of the channel and the velocity of the separated microspheres are detected with an accuracy of 1.4μm and 0.08 mm/s respectively. Throughout the measurements of the height...

  17. Three-dimensional positioning with optofluidic microscope

    DEFF Research Database (Denmark)

    Vig, Asger Laurberg; Marie, Rodolphe; Jensen, Eric

    2010-01-01

    This paper reports on-chip based optical detection with three-dimensional spatial resolution by integration of an optofluidic microscope (OFM) in a microfluidic pinched flow fractionation (PFF) separation device. This setup also enables on-chip particle image velocimetry (PIV). The position...... a conventional fluorescence microscope as readout. The size separated microspheres are detected by OFM with an accuracy of ≤ 0.92 μm. The position in the height of the channel and the velocity of the separated microspheres are detected with an accuracy of 1.4 μm and 0.08 mm/s respectively. Throughout...

  18. The clinical microscope and direct composite veneer

    DEFF Research Database (Denmark)

    Pascotto, Renata C; Benetti, Ana Raquel

    2010-01-01

    This paper presents the advantages and limitations related to the use of a clinical microscope in restorative dentistry, and it demonstrates the aid of magnification during preparation and restoration of a direct composite veneer. Good illumination and visibility is important to adequately viewin...... the adjacent dental tissues so that the resin composite buildup can mimic natural teeth. The reproduction of details results in a naturally esthetic direct veneer.......This paper presents the advantages and limitations related to the use of a clinical microscope in restorative dentistry, and it demonstrates the aid of magnification during preparation and restoration of a direct composite veneer. Good illumination and visibility is important to adequately viewing...

  19. Microscopic treatment of solute trapping and drag

    Science.gov (United States)

    Humadi, Harith; Hoyt, J. J.; Provatas, Nikolas

    2016-01-01

    The long wavelength limit of a recent microscopic phase-field crystal (PFC) theory of a binary alloy mixture is used to derive an analytical approximation for the segregation coefficient as a function of the interface velocity, and relate it to the two-point correlation function of the liquid and the thermodynamic properties of solid and liquid phases. Our results offer the first analytical derivation of solute segregation from a microscopic model, and support recent molecular dynamics and numerical PFC simulations. Our results also provide an independent framework, motivated from classical density functional theory, from which to elucidate the fundamental nature of solute drag, which is still highly contested in the literature.

  20. An innovative approach in microscopic endodontics

    Science.gov (United States)

    Mittal, Sunandan; Kumar, Tarun; Sharma, Jyotika; Mittal, Shifali

    2014-01-01

    The introduction of the dental operating microscope was a turning point in the history of dentistry. It triggered a rapid transition from the conventional world of macro-dentistry to the precise, detailed world of micro-dentistry. However, working at these higher-power magnifications brings the clinician into the realm where even slight hand movements are disruptive. Physiologic hand tremor is a problem resulting in difficulty in mouth mirror placement. Hence, in this paper, a new instrument was designed to overcome the drawback of hand tremors during microscopic endodontics. PMID:24944459

  1. Microscopic tunneling theory of long Josephson junctions

    DEFF Research Database (Denmark)

    Grønbech-Jensen, N.; Hattel, Søren A.; Samuelsen, Mogens Rugholm

    1992-01-01

    We present a numerical scheme for solving a nonlinear partial integro-differential equation with nonlocal time dependence. The equation describes the dynamics in a long Josephson junction modeled by use of the microscopic theory for tunneling between superconductors. We demonstrate that the detai......We present a numerical scheme for solving a nonlinear partial integro-differential equation with nonlocal time dependence. The equation describes the dynamics in a long Josephson junction modeled by use of the microscopic theory for tunneling between superconductors. We demonstrate...... that the detailed behavior of a solitonic mode (fluxon dynamics) in the junction is different from the results of the conventional perturbed sine-Gordon model....

  2. Microscopic model of a phononic refrigerator

    Science.gov (United States)

    Arrachea, Liliana; Mucciolo, Eduardo R.; Chamon, Claudio; Capaz, Rodrigo B.

    2012-09-01

    We analyze a simple microscopic model to pump heat from a cold to a hot reservoir in a nanomechanical system. The model consists of a one-dimensional chain of masses and springs coupled to a back gate through which a time-dependent perturbation is applied. The action of the gate creates a moving phononic barrier by locally pinning a mass. We solve the problem numerically using a nonequilibrium Green's function technique. For low driving frequencies and for sharp traveling barriers, we show that this microscopic model realizes a phonon refrigerator.

  3. Small-size low-temperature scanning tunnel microscope

    International Nuclear Information System (INIS)

    Al'tfeder, I.B.; Khajkin, M.S.

    1989-01-01

    A small-size scanning tunnel microscope, designed for operation in transport helium-filled Dewar flasks is described. The microscope design contains a device moving the pin to the tested sample surface and a piezoelectric fine positioning device. High vibration protection of the microscope is provided by its suspension using silk threads. The small-size scanning tunnel microscope provides for atomic resolution

  4. 21 CFR 864.3600 - Microscopes and accessories.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Microscopes and accessories. 864.3600 Section 864... Microscopes and accessories. (a) Identification. Microscopes and accessories are optical instruments used to enlarge images of specimens, preparations, and cultures for medical purposes. Variations of microscopes...

  5. Science 101: How Does an Electron Microscope Work?

    Science.gov (United States)

    Robertson, Bill

    2013-01-01

    Contrary to popular opinion, electron microscopes are not used to look at electrons. They are used to look for structure in things that are too small to observe with an optical microscope, or to obtain images that are magnified much more than is obtainable with an optical microscope. To understand how electron microscopes work, it will help to go…

  6. Microscopic properties of superdeformed nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Karlsson, Lennart B

    1999-04-01

    are made based on effective alignments. The region is connected to, and compared with, previously investigated {sup 146-153}Gd nuclei. The two regions show similarities but it appears difficult to get consistent alignments in the whole region around {sup 143}Eu

  7. Nanoparticle Imaging with Polarization Interferometric Nonlinear Confocal Microscope

    OpenAIRE

    Fujita, Kohei; Egami, Chikara

    2014-01-01

    Polarization interferometric nonlinear confocal microscope has been developed for single nanoparticle analysis of drug delivery system (DDS). The microscope is a system based on a low cost and low power continuous wave (CW) laser light source. Also, the microscope observed shape anisotropy of the 200 nm diameter nanoparticle. According to nanoparticle imaging and CTF (contrast transfer function) curve observation of the microscope, three-dimensional resolution of the microscope measured up to...

  8. Spin microscope based on optically detected magnetic resonance

    Science.gov (United States)

    Berman, Gennady P.; Chernobrod, Boris M.

    2007-12-11

    The invention relates to scanning magnetic microscope which has a photoluminescent nanoprobe implanted in the tip apex of an atomic force microscope (AFM), a scanning tunneling microscope (STM) or a near-field scanning optical microscope (NSOM) and exhibits optically detected magnetic resonance (ODMR) in the vicinity of unpaired electron spins or nuclear magnetic moments in the sample material. The described spin microscope has demonstrated nanoscale lateral resolution and single spin sensitivity for the AFM and STM embodiments.

  9. MACROSCOPICAL AND MICROSCOPICAL STUDIES ON THE ...

    African Journals Online (AJOL)

    Caesalpinia crista leaves are bipinnate of about six pairs with alternate leaflets while the stem us fibrous, cylindrical hollow and prickly. Microscopical examination revealed the presence of strained cuticle, straight-walled epidermal cells, paracytic stomata, unicellular covering trichomes, fibres, prisms as well as cluster of ...

  10. Energy electron analyzers raster electron microscope

    International Nuclear Information System (INIS)

    Dremova, N.N.; Raj, Eh.I.; Robinson, V.N.

    1995-01-01

    Spectrometers of back-scattered and secondary electrons used in a raster electron microscope designed to study multilayer structures and potential relief at the solid-state body surface, are described. Their possible applications are demonstrated using microelectronics devices as an example

  11. Wavelet Transform - A New Mathematical Microscope

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 9; Issue 3. Wavelet Transform - A New Mathematical Microscope. Sachin P Nanavati Prasanta K Panigrahi. General Article Volume 9 Issue 3 March 2004 pp 50-64. Fulltext. Click here to view fulltext PDF. Permanent link:

  12. Microscopic Derivation of Ginzburg-Landau Theory

    DEFF Research Database (Denmark)

    Frank, Rupert; Hainzl, Christian; Seiringer, Robert

    2012-01-01

    We give the first rigorous derivation of the celebrated Ginzburg-Landau (GL) theory, starting from the microscopic Bardeen-Cooper-Schrieffer (BCS) model. Close to the critical temperature, GL arises as an effective theory on the macroscopic scale. The relevant scaling limit is semiclassical...

  13. Exploring the environmental transmission electron microscope

    DEFF Research Database (Denmark)

    Wagner, Jakob B.; Cavalca, Filippo; Damsgaard, Christian D.

    2012-01-01

    of the opportunities that the environmental TEM (ETEM) offers when combined with other in situ techniques will be explored, directly in the microscope, by combining electron-based and photon-based techniques and phenomena. In addition, application of adjacent setups using sophisticated transfer methods...

  14. Mesooptical microscope as a tomographical device

    International Nuclear Information System (INIS)

    Soroko, L.M.

    1989-01-01

    It is shown that there are at least four regions which are common for the mesooptical microscopes, on the one hand, and for the reconstructed tomography, on the other hand. The following characteristics of the mesooptical microscope show the tomographical properties: the structure of the output data concerning the orientation and the position in space of the straight-line objects going at small angles with the perpendicular to the given tomographic plane, the behaviour of the two-dimensional fourier-transform of the straight-line object in the course of the rotation of this object with respect to the specified axis in space, the scanning algorithm of the nuclear emulsion volume by the fence-like illuminated region in the mesooptical microscope for searching for particle tracks going parallel to the optical axis of the microscope, and, finally, the fact that the mesooptical images of the straight-line particle tracks with a common vertex in the nuclear emulsion lie on the sinogram. 12 refs.; 16 figs

  15. The Titan Environmental Transmission Electron Microscope

    DEFF Research Database (Denmark)

    Hansen, Thomas Willum; Wagner, Jakob Birkedal; Jinschek, Jörg R.

    2009-01-01

    University of Denmark (DTU) provides a unique combination of techniques for studying materials of interest to the catalytic as well as the electronics and other communities [5]. DTU’s ETEM is based on the FEI Titan platform providing ultrahigh microscope stability pushing the imaging resolution into the sub...

  16. Stick-on microscope for smartphones

    Science.gov (United States)

    Lee, W. M.

    2014-02-01

    In this paper, I demonstrate a low cost light weight microscope device that is compatible with any smartphone camera. The device amplifies the imaging resolution of a smartphone camera by three orders of magnitude from millimeters to sub-micrometers, while costing approximately USD$ 2.

  17. Compact, common path quantitative phase microscopic techniques ...

    Indian Academy of Sciences (India)

    2014-01-05

    Jan 5, 2014 ... One of the ways to retrieve object height/thickness information is to employ quantitative phase microscopic (QPM) techniques. Interferometric QPM techniques are widely used for this. Digital holographic microscopy (DHM) is one of the stateof-the-art methods for quantitative three-dimensional (3D) imaging.

  18. Microscopic polyangeitis, report of a case

    International Nuclear Information System (INIS)

    Malagon, Patricia; Suarez, Martha Lucia

    1998-01-01

    Polyarteritis or microscopic polyangeitis is a systemic necrotizing vasculitis associated with the lung-kidney syndrome. It presents with diffuse alveolar hemorrhage and necrotizing glomerulonephritis with multisystem involvement. A case is presented of a 50 years old male with its clinical and imaging findings

  19. Microscopic Description of Le Chatelier's Principle

    Science.gov (United States)

    Novak, Igor

    2005-01-01

    A simple approach that "demystifies" Le Chatelier's principle (LCP) and simulates students to think about fundamental physical background behind the well-known principles is presented. The approach uses microscopic descriptors of matter like energy levels and populations and does not require any assumption about the fixed amount of substance being…

  20. Of Mechanisms, Microscopes and Methyl isocyanate

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 13; Issue 3. Of Mechanisms, Microscopes and Methyl isocyanate. S Sriramachari Sujata Varadarajan. Face to Face Volume 13 Issue 3 March 2008 pp 292-306. Fulltext. Click here to view fulltext PDF. Permanent link:

  1. Wavelet Transform-A New Mathematical Microscope

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 9; Issue 3. Wavelet Transform - A New Mathematical Microscope. Sachin P Nanavati Prasanta K Panigrahi. General Article Volume 9 Issue 3 March 2004 pp 50-64. Fulltext. Click here to view fulltext PDF. Permanent link:

  2. Reasoning about Magnetism at the Microscopic Level

    Science.gov (United States)

    Cheng, Meng-Fei; Cheng, Yufang; Hung, Shuo-Hsien

    2014-01-01

    Based on our experience of teaching physics in middle and senior secondary school, we have found that students have difficulty in reasoning at the microscopic level. Their reasoning is limited to the observational level so they have problems in developing scientific models of magnetism. Here, we suggest several practical activities and the use of…

  3. Seamless stitching of tile scan microscope images.

    Science.gov (United States)

    Legesse, F B; Chernavskaia, O; Heuke, S; Bocklitz, T; Meyer, T; Popp, J; Heintzmann, R

    2015-06-01

    For diagnostic purposes, optical imaging techniques need to obtain high-resolution images of extended biological specimens in reasonable time. The field of view of an objective lens, however, is often smaller than the sample size. To image the whole sample, laser scanning microscopes acquire tile scans that are stitched into larger mosaics. The appearance of such image mosaics is affected by visible edge artefacts that arise from various optical aberrations which manifest in grey level jumps across tile boundaries. In this contribution, a technique for stitching tiles into a seamless mosaic is presented. The stitching algorithm operates by equilibrating neighbouring edges and forcing the brightness at corners to a common value. The corrected image mosaics appear to be free from stitching artefacts and are, therefore, suited for further image analysis procedures. The contribution presents a novel method to seamlessly stitch tiles captured by a laser scanning microscope into a large mosaic. The motivation for the work is the failure of currently existing methods for stitching nonlinear, multimodal images captured by our microscopic setups. Our method eliminates the visible edge artefacts that appear between neighbouring tiles by taking into account the overall illumination differences among tiles in such mosaics. The algorithm first corrects the nonuniform brightness that exists within each of the tiles. It then compensates for grey level differences across tile boundaries by equilibrating neighbouring edges and forcing the brightness at the corners to a common value. After these artefacts have been removed further image analysis procedures can be applied on the microscopic images. Even though the solution presented here is tailored for the aforementioned specific case, it could be easily adapted to other contexts where image tiles are assembled into mosaics such as in astronomical or satellite photos. © 2015 The Authors Journal of Microscopy © 2015 Royal

  4. Dynamic-scanning-electron-microscope study of friction and wear

    Science.gov (United States)

    Brainard, W. A.; Buckley, D. H.

    1974-01-01

    A friction and wear apparatus was built into a real time scanning electron microscope (SEM). The apparatus and SEM comprise a system which provides the capability of performing dynamic friction and wear experiments in situ. When the system is used in conjunction with dispersive X-ray analysis, a wide range of information on the wearing process can be obtained. The type of wear and variation with speed, load, and time can be investigated. The source, size, and distribution of wear particles can be determined and metallic transferal observed. Some typical results obtained with aluminum, copper, and iron specimens are given.

  5. Nonequilibrium Microscopic Distribution of Thermal Current in Particle Systems

    KAUST Repository

    Yukawa, Satoshi

    2009-02-15

    A nonequilibrium distribution function of microscopic thermal current is studied by a direct numerical simulation in a thermal conducting steady state of particle systems. Two characteristic temperatures of the thermal current are investigated on the basis of the distribution. It is confirmed that the temperature depends on the current direction; Parallel temperature to the heat-flux is higher than antiparallel one. The difference between the parallel temperature and the antiparallel one is proportional to a macroscopic temperature gradient. ©2009 The Physical Society of Japan.

  6. A MEANS FOR CALIBRATING A MICROSCOPE, A METHOD OF PREPARING THE MEANS AND A METHOD OF CALIBRATING A MICROSCOPE

    DEFF Research Database (Denmark)

    2005-01-01

    A means or artefact for calibrating the height/depth or Z axis of a microscope, such as a confocal microscope, an interference microscope or a Scanning Electron Microscope. The artefact comprises a number of tapering or pie-shaped, parallel surfaces each extending from a central axis, whereby all...... surfaces and heights are visible independently of the magnification of the microscope. Thus, the full height range may be calibrated and the linearity thereof checked independently of the magnification....

  7. Modernization of the REHMP-2 scanning electron microscope to study semiconductors

    International Nuclear Information System (INIS)

    Nazarkin, V.N.; Korob, E.B.

    1977-01-01

    The REMP-2 raster microscope has been modernized in order to adjust it for investigations of semiconductors by diode current signal (DCS) technique. The changes in the secondary electronic image circuit provided for its higher reliability. Presentation of DCS on the screen of the electron beam tube of the microscope display involved either modulations of the screen brightness or modulations of deviation on the screen and at the recorder. With the use of a recorder it was possible to study objects of an essentially greater area. A sensitive amplifier of DCS provides for working with weak signals and for quantitative investigations. Investigations of semiconductors at low temperatures is carried out with the help of an objective table cooled by liquid nitrogen. The illustrations show some capacities of the modernized REMP-2 microscope for DCS investigations of semiconductors

  8. UV-visible microscope spectrophotometric polarization and dichroism with increased discrimination power in forensic analysis

    Science.gov (United States)

    Purcell, Dale Kevin

    Microanalysis of transfer (Trace) evidence is the application of a microscope and microscopical techniques for the collection, observation, documentation, examination, identification, and discrimination of micrometer sized particles or domains. Microscope spectrophotometry is the union of microscopy and spectroscopy for microanalysis. Analytical microspectroscopy is the science of studying the emission, reflection, transmission, and absorption of electromagnetic radiation to determine the structure or chemical composition of microscopic-size materials. Microscope spectrophotometry instrument designs have evolved from monochromatic illumination which transmitted through the microscope and sample and then is detected by a photometer detector (photomultiplier tube) to systems in which broad-band (white light) illumination falls incident upon a sample followed by a non-scanning grating spectrometer equipped with a solid-state multi-element detector. Most of these small modern spectrometers are configured with either silicon based charged-couple device detectors (200-950 nm) or InGaAs based diode array detectors (850-2300 nm) with computerized data acquisition and signal processing being common. A focus of this research was to evaluate the performance characteristics of various modern forensic (UV-Vis) microscope photometer systems as well as review early model instrumental designs. An important focus of this research was to efficiently measure ultraviolet-visible spectra of microscopically small specimens for classification, differentiation, and possibly individualization. The first stage of the project consisted of the preparation of microscope slides containing neutral density filter reference materials, molecular fluorescence reference materials, and dichroic reference materials. Upon completion of these standard slide preparations analysis began with measurements in order to evaluate figures of merit for comparison of the instruments investigated. The figures of

  9. 3D-Mössbauer spectroscopic microscope for mc-Si solar cell evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Ino, Y., E-mail: y-ino@ob.sist.ac.jp; Soejima, H.; Hayakawa, K.; Yukihira, K.; Tanaka, K.; Fujita, H.; Watanabe, T. [Shizuoka Institute of Science and Technology (Japan); Ogai, K.; Moriguchi, K.; Harada, Y. [APCO. Ltd. (Japan); Yoshida, Y. [Shizuoka Institute of Science and Technology (Japan)

    2016-12-15

    A 3D-Mössbauer Spectroscopic Microscope is developed to evaluate Fe impurities in multi-crystalline Si solar cells, which combines the Mössbauer spectroscopic microscope with a scanning electron microscope (SEM), an electron beam induced current (EBIC), an electron backscatter diffraction (EBSD), and an electron energy analyzer (HV-CSA). In addition, a new moving-coil-actuator with a liner encoder of 100 nm-resolution is incorporated for the operations with both a constant velocity and a constant acceleration mode successfully with the same precision as that obtained by the conventional transducers. Furthermore, a new multi-capillary X-ray lens is designed to achieve a γ-ray spot size less than 100 μm in diameter. The new microscope provides us to investigate the space correlation between Fe impurities and the lattice defects such as grain boundaries in multi-crystalline Si solar cells.

  10. Virtual reality microscope versus conventional microscope regarding time to diagnosis: an experimental study.

    Science.gov (United States)

    Randell, Rebecca; Ruddle, Roy A; Mello-Thoms, Claudia; Thomas, Rhys G; Quirke, Phil; Treanor, Darren

    2013-01-01

      To create and evaluate a virtual reality (VR) microscope that is as efficient as the conventional microscope, seeking to support the introduction of digital slides into routine practice.   A VR microscope was designed and implemented by combining ultra-high-resolution displays with VR technology, techniques for fast interaction, and high usability. It was evaluated using a mixed factorial experimental design with technology and task as within-participant variables and grade of histopathologist as a between-participant variable. Time to diagnosis was similar for the conventional and VR microscopes. However, there was a significant difference in the mean magnification used between the two technologies, with participants working at a higher level of magnification on the VR microscope.   The results suggest that, with the right technology, efficient use of digital pathology for routine practice is a realistic possibility. Further work is required to explore what magnification is required on the VR microscope for histopathologists to identify diagnostic features, and the effect on this of the digital slide production process. © 2012 Blackwell Publishing Limited.

  11. The choice of microscopes for use in genitourinary medicine clinics.

    Science.gov (United States)

    Cremer, A W

    1990-01-01

    The current wide choice of microscopes and the use of the microscope as a diagnostic tool is discussed. The formation of images and the aberrations which occur with lenses and the ways in which these are corrected are described. The functions of eye pieces and illuminating systems are presented. The requirements for microscopes in every day use, research microscopes and portable microscopes are described, and suggestions made as to how these requirements may be fulfilled. Brief comments on the care and maintenance of microscopes are made, and a list of manufacturers and suppliers appended. PMID:2196218

  12. EXTRACELLULAR CELLULOLYTIC COMPLEXES PRODUCTION BY MICROSCOPIC FUNGI

    Directory of Open Access Journals (Sweden)

    S. O. Syrchin

    2015-10-01

    Full Text Available The aim of this work was to screen and to study the effect of inducers on the synthesis of the cellulolytic enzyme complexes by microscopic fungi. Cellulolytic and xylanolytic activities were determined by reducing sugar with DNS reagent, and β-glucosidase activity by pNPG hydrolysis. The enzyme preparations were obtained by ammonium sulphate precipitation. Among 32 studied strains of microscopic fungi 14 produced cellulo- and xylanolytic enzyme complexes. Fusarium sp. 5 and Fennellia sp. 2806 demonstrated the highest levels of all studied enzyme activities. Enzyme preparations with high endo-, exoglucanase, xylanase and β-glucosidase activities were obtained from these strains. Fusarium sp. 5 and Fennellia sp. 2806 were active producers of cellulase enzyme complexes during growth on natural substrates. It was shown that inductors of cellulolytic enzymes in Fusarium sp. 5 and Fennellia sp. 2806 differed from the ones in Trichoderma reesei.

  13. Development of Scanning Ultrafast Electron Microscope Capability.

    Energy Technology Data Exchange (ETDEWEB)

    Collins, Kimberlee Chiyoko [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Talin, Albert Alec [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Chandler, David W. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Michael, Joseph R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-11-01

    Modern semiconductor devices rely on the transport of minority charge carriers. Direct examination of minority carrier lifetimes in real devices with nanometer-scale features requires a measurement method with simultaneously high spatial and temporal resolutions. Achieving nanometer spatial resolutions at sub-nanosecond temporal resolution is possible with pump-probe methods that utilize electrons as probes. Recently, a stroboscopic scanning electron microscope was developed at Caltech, and used to study carrier transport across a Si p-n junction [ 1 , 2 , 3 ] . In this report, we detail our development of a prototype scanning ultrafast electron microscope system at Sandia National Laboratories based on the original Caltech design. This effort represents Sandia's first exploration into ultrafast electron microscopy.

  14. Fluorescence microscope by using computational ghost imaging

    Directory of Open Access Journals (Sweden)

    Mizutani Yasuhiro

    2015-01-01

    Full Text Available We propose a fluorescence microscope by using the computational Ghost imaging (CGI for observing a living cell for a long duration over an hour. There is a problem for observing a cell about light-induced bleaching fora ling-term observation.Toover come the problem, we focused on an advantageof sensitivityof the CGI as second order colleration for an imaging with weak intensity excitation light. Setting for the CGI, a DMD projector was installed at an eye-piece part of a microscope and fluorescent light was detected using a bucket detectorofa photo-multiplier tube.Asaresults,wehaveshownthe imagingadvantageoftheCGI under weak light intensity, in addition, we have demonstrated to detect fluorescence images of biological samples for one day.

  15. Optics of high-performance electron microscopes*

    Science.gov (United States)

    Rose, H H

    2008-01-01

    During recent years, the theory of charged particle optics together with advances in fabrication tolerances and experimental techniques has lead to very significant advances in high-performance electron microscopes. Here, we will describe which theoretical tools, inventions and designs have driven this development. We cover the basic theory of higher-order electron optics and of image formation in electron microscopes. This leads to a description of different methods to correct aberrations by multipole fields and to a discussion of the most advanced design that take advantage of these techniques. The theory of electron mirrors is developed and it is shown how this can be used to correct aberrations and to design energy filters. Finally, different types of energy filters are described. PMID:27877933

  16. Optics of high-performance electron microscopes.

    Science.gov (United States)

    Rose, H H

    2008-01-01

    During recent years, the theory of charged particle optics together with advances in fabrication tolerances and experimental techniques has lead to very significant advances in high-performance electron microscopes. Here, we will describe which theoretical tools, inventions and designs have driven this development. We cover the basic theory of higher-order electron optics and of image formation in electron microscopes. This leads to a description of different methods to correct aberrations by multipole fields and to a discussion of the most advanced design that take advantage of these techniques. The theory of electron mirrors is developed and it is shown how this can be used to correct aberrations and to design energy filters. Finally, different types of energy filters are described.

  17. Polarized differential-phase laser scanning microscope

    International Nuclear Information System (INIS)

    Chou Chien; Lyu, C.-W.; Peng, L.-C.

    2001-01-01

    A polarized differential-phase laser scanning microscope, which combines a polarized optical heterodyne Mach-Zehnder interferometer and a differential amplifier to scan the topographic image of a surface, is proposed. In the experiment the differential amplifier, which acts as a PM-AM converter, in the experiment, converting phase modulation (PM) into amplitude modulation (AM). Then a novel, to our knowledge, phase demodulator was proposed and implemented for the differential-phase laser scanning microscope. An optical grating (1800 lp/mm) was imaged. The lateral and the depth resolutions of the imaging system were 0.5 μm and 1 nm, respectively. The detection accuracy, which was limited by the reflectivity variation of the test surface, is discussed

  18. Analytical model of the optical vortex microscope.

    Science.gov (United States)

    Płocinniczak, Łukasz; Popiołek-Masajada, Agnieszka; Masajada, Jan; Szatkowski, Mateusz

    2016-04-20

    This paper presents an analytical model of the optical vortex scanning microscope. In this microscope the Gaussian beam with an embedded optical vortex is focused into the sample plane. Additionally, the optical vortex can be moved inside the beam, which allows fine scanning of the sample. We provide an analytical solution of the whole path of the beam in the system (within paraxial approximation)-from the vortex lens to the observation plane situated on the CCD camera. The calculations are performed step by step from one optical element to the next. We show that at each step, the expression for light complex amplitude has the same form with only four coefficients modified. We also derive a simple expression for the vortex trajectory of small vortex displacements.

  19. Scanning microscopic four-point conductivity probes

    DEFF Research Database (Denmark)

    Petersen, Christian Leth; Hansen, Torben Mikael; Bøggild, Peter

    2002-01-01

    A method for fabricating microscopic four-point probes is presented. The method uses silicon-based microfabrication technology involving only two patterning steps. The last step in the fabrication process is an unmasked deposition of the conducting probe material, and it is thus possible to select...... the conducting material either for a silicon wafer or a single probe unit. Using shadow masking photolithography an electrode spacing (pitch) down to 1.1 mum was obtained, with cantilever separation down to 200 run. Characterisation measurements have shown the microscopic probes to be mechanically very flexible...... and robust. Repeated conductivity measurements on polythiophene films in the same surface area are reproduced within an accuracy of 3%. Automated nanoresolution position control allows scanning across millimetre sized areas, in order to create high spatial resolution maps of the in-plane conductivity....

  20. Portable smartphone based quantitative phase microscope

    Science.gov (United States)

    Meng, Xin; Tian, Xiaolin; Yu, Wei; Kong, Yan; Jiang, Zhilong; Liu, Fei; Xue, Liang; Liu, Cheng; Wang, Shouyu

    2018-01-01

    To realize portable device with high contrast imaging capability, we designed a quantitative phase microscope using transport of intensity equation method based on a smartphone. The whole system employs an objective and an eyepiece as imaging system and a cost-effective LED as illumination source. A 3-D printed cradle is used to align these components. Images of different focal planes are captured by manual focusing, followed by calculation of sample phase via a self-developed Android application. To validate its accuracy, we first tested the device by measuring a random phase plate with known phases, and then red blood cell smear, Pap smear, broad bean epidermis sections and monocot root were also measured to show its performance. Owing to its advantages as accuracy, high-contrast, cost-effective and portability, the portable smartphone based quantitative phase microscope is a promising tool which can be future adopted in remote healthcare and medical diagnosis.

  1. Scanning tunneling microscope assembly, reactor, and system

    Science.gov (United States)

    Tao, Feng; Salmeron, Miquel; Somorjai, Gabor A

    2014-11-18

    An embodiment of a scanning tunneling microscope (STM) reactor includes a pressure vessel, an STM assembly, and three spring coupling objects. The pressure vessel includes a sealable port, an interior, and an exterior. An embodiment of an STM system includes a vacuum chamber, an STM reactor, and three springs. The three springs couple the STM reactor to the vacuum chamber and are operable to suspend the scanning tunneling microscope reactor within the interior of the vacuum chamber during operation of the STM reactor. An embodiment of an STM assembly includes a coarse displacement arrangement, a piezoelectric fine displacement scanning tube coupled to the coarse displacement arrangement, and a receiver. The piezoelectric fine displacement scanning tube is coupled to the coarse displacement arrangement. The receiver is coupled to the piezoelectric scanning tube and is operable to receive a tip holder, and the tip holder is operable to receive a tip.

  2. Realistic microscopic level densities for spherical nuclei

    International Nuclear Information System (INIS)

    Cerf, N.

    1994-01-01

    Nuclear level densities play an important role in nuclear reactions such as the formation of the compound nucleus. We develop a microscopic calculation of the level density based on a combinatorial evaluation from a realistic single-particle level scheme. This calculation makes use of a fast Monte Carlo algorithm allowing us to consider large shell model spaces which could not be treated previously in combinatorial approaches. Since our model relies on a microscopic basis, it can be applied to exotic nuclei with more confidence than the commonly used semiphenomenological formuals. An exhaustive comparison of our predicted neutron s-wave resonance spacings with experimental data for a wide range of nuclei is presented

  3. Scanning electron microscope view of iron crystal

    Science.gov (United States)

    1972-01-01

    A scanning electron microscope photograph of iron crystals which grow in a small vug or cavity in a recrystallized breccia (fragmented rock) from the Apollo 15 Hadley-Apennino lunar landing site. The largest crystal is three microns across. Perfectly developed crystals such as these indicate slow formation from a hot vapor as the rock was cooling. The crystals are resting on an interlocking lattice of pyroxene (calsium-magnesium-iron silicate).

  4. Atomic Force Microscope for Imaging and Spectroscopy

    Science.gov (United States)

    Pike, W. T.; Hecht, M. H.; Anderson, M. S.; Akiyama, T.; Gautsch, S.; deRooij, N. F.; Staufer, U.; Niedermann, Ph.; Howald, L.; Mueller, D.

    2000-01-01

    We have developed, built, and tested an atomic force microscope (AFM) for extraterrestrial applications incorporating a micromachined tip array to allow for probe replacement. It is part of a microscopy station originally intended for NASA's 2001 Mars lander to identify the size, distribution, and shape of Martian dust and soil particles. As well as imaging topographically down to nanometer resolution, this instrument can be used to reveal chemical information and perform infrared and Raman spectroscopy at unprecedented resolution.

  5. Imaging differential polarization microscope with electronic readout

    International Nuclear Information System (INIS)

    Mickols, W.; Tinoco, I.; Katz, J.E.; Maestre, M.F.; Bustamante, C.

    1985-01-01

    A differential polarization microscope forms two images: one of the transmitted intensity and the other due to the change in intensity between images formed when different polarizations of light are used. The interpretation of these images for linear dichroism and circular dichroism are described. The design constraints on the data acquisition systems and the polarization modulation are described. The advantage of imaging several biological systems which contain optically anisotropic structures are described

  6. The microscopic magnetization: concept and application*

    International Nuclear Information System (INIS)

    Hirst, L.L.

    1997-01-01

    In this tutorial review a definition of the magnetization which can be used at the microscopic and quantum-mechanical level is motivated and developed. Its implications for the problem of reconstructing the magnetization in a crystal from magnetic neutron-diffraction data or from band-theoretical calculations are discussed, paying special attention to the relation between spin and orbital contributions. copyright 1997 The American Physical Society

  7. Microscopic Engine Powered by Critical Demixing

    Science.gov (United States)

    Schmidt, Falko; Magazzù, Alessandro; Callegari, Agnese; Biancofiore, Luca; Cichos, Frank; Volpe, Giovanni

    2018-02-01

    We experimentally demonstrate a microscopic engine powered by the local reversible demixing of a critical mixture. We show that, when an absorbing microsphere is optically trapped by a focused laser beam in a subcritical mixture, it is set into rotation around the optical axis of the beam because of the emergence of diffusiophoretic propulsion. This behavior can be controlled by adjusting the optical power, the temperature, and the criticality of the mixture.

  8. Digital management of an electron microscope unit

    International Nuclear Information System (INIS)

    Elea, N.; Dickson, M.; Munroe, P.

    2002-01-01

    Full text: Electron microscope units, especially those such as ours, which operate as a central infrastructural facility are increasingly asked to provide more service, over more instruments with decreasing, or limited, financial resources. We believe that staff time is best used performing electron microscopy, assisting users and maintaining instrumentation rather than in the pursuit of red tape. One solution to this problem has been the creation of a control system which performs all routine acts of data management, such as the archiving and accessing of digital data, providing access to bookings, and most importantly in the era of user pays services, logging time and billing users. The system we have created, developed and expanded allows the users themselves to access our server through any web-browser and make their own bookings or access and manipulate their data. Users themselves must log on to a microscope through swipecard readers before it can be used and log-off after use. Their time is logged precisely and an exquisitely fair user pays systems can be operated by transferring logged usage time to spreadsheets to calculate charges. Furthermore, this system acts as a method of user authentication and can be used to bar incompetent or unauthorised users. The system has recently been upgraded to increase its utility to include sensors that monitor the electron microscope operating environment, such as magnetic field, room temperature, water flow etc, so that if these parameters depart significantly from optimum levels electron microscope unit staff may be alerted. In this presentation the structure of our system will be described and the advantages and disadvantages of such a system will be discussed. Copyright (2002) Australian Society for Electron Microscopy Inc

  9. Scanning Probe Microscope-Based Fluid Dispensing

    Directory of Open Access Journals (Sweden)

    Murali Krishna Ghatkesar

    2014-10-01

    Full Text Available Advances in micro and nano fabrication technologies have enabled fabrication of smaller and more sensitive devices for applications not only in solid-state physics but also in medicine and biology. The demand for devices that can precisely transport material, specifically fluids are continuously increasing. Therefore, integration of various technologies with numerous functionalities in one single device is important. Scanning probe microscope (SPM is one such device that has evolved from atomic force microscope for imaging to a variety of microscopes by integrating different physical and chemical mechanisms. In this article, we review a particular class of SPM devices that are suited for fluid dispensing. We review their fabrication methods, fluid-pumping mechanisms, real-time monitoring of dispensing, physics of dispensing, and droplet characterization. Some of the examples where these probes have already been applied are also described. Finally, we conclude with an outlook and future scope for these devices where femtolitre or smaller volumes of liquid handling are needed.

  10. Optical microscopic imaging based on VRML language

    Science.gov (United States)

    Zhang, Xuedian; Zhang, Zhenyi; Sun, Jun

    2009-11-01

    As so-called VRML (Virtual Reality Modeling Language), is a kind of language used to establish a model of the real world or a colorful world made by people. As in international standard, VRML is the main kind of program language based on the "www" net building, which is defined by ISO, the kind of MIME is x-world or x-VRML. The most important is that it has no relationship with the operating system. Otherwise, because of the birth of VRML 2.0, its ability of describing the dynamic condition gets better, and the interaction of the internet evolved too. The use of VRML will bring a revolutionary change of confocal microscope. For example, we could send different kinds of swatch in virtual 3D style to the net. On the other hand, scientists in different countries could use the same microscope in the same time to watch the same samples by the internet. The mode of sending original data in the model of text has many advantages, such as: the faster transporting, the fewer data, the more convenient updating and fewer errors. In the following words we shall discuss the basic elements of using VRML in the field of Optical Microscopic imaging.

  11. Microscopic Irreversibility and the H Theorem

    Science.gov (United States)

    Magpantay, Jose A.

    2013-02-01

    Time-reversal had always been assumed to be a symmetry of physics at the fundamental level. In this paper we will explore the violations of time-reversal symmetry at the fundamental level and the consequence on thermodynamic systems. First, we will argue from current physics that the universe dynamics is not time-reversal invariant. Second, we will argue that any thermodynamic system cannot be isolated completely from the universe. We then discuss how these two make the dynamics of thermodynamics systems very weakly irreversible at the classical and quantum level. Since time-reversal is no longer a symmetry of realistic systems, the problem of how macroscopic irreversibility arises from microscopic reversibility becomes irrelevant because there is no longer microscopic reversibility. At the classical level of a thermodynamic system, we show that the H theorem of Boltzmann is still valid even without microscopic reversibility. We do this by deriving a modified H theorem, which still shows entropy monotonically increasing. At the quantum level, we explicitly show the effect of CP violation, small irreversible changes on the internal states of the nuclear and atomic energy levels of thermodynamic systems. Thus, we remove Loschmidt's objection to Boltzmann's ideas.

  12. Schwarzschild microscopes in vacuum ultraviolet and soft X-ray regions

    International Nuclear Information System (INIS)

    Watanabe, M.; Yanagihara, M.; Ejima, T.; Toyoda, M.; Kondo, Y.; Hatano, T.; Tsuru, T.; Yamamoto, M.

    2005-01-01

    Microscopes in vacuum ultraviolet and soft X-ray regions using a normal incidence type of Schwarzschild objective are reviewed. The objective consists of a concave mirror and a convex mirror coated with a high reflectance multilayer, having a large numerical aperture comparing with other objectives. The microscopes have been used to diagnose inertia-confinement-fusion plasmas, and to investigate small samples or microstructures of inorganic and organic materials by imaging them using laboratory light sources. Synchrotron radiation has been also used to obtain a microbeam for a photoelectron scanning microscope with a spatial resolution of 0.1 μm. The structure and performance of two laboratory microscopes developed at Tohoku University are demonstrated. One of them is a soft X-ray emission imaging microscope. An image of an artificial pattern made of W and SiO 2 on Si wafer by focusing Si L emission was presented. The other is an ultraviolet photoelectron scanning microscope using a He (helium) gas discharge lamp. The valence band spectra of a microcrystal of FeWO 4 were presented. Furthermore other applications such as demagnifying optics for lithography and optics to gather fluorescence for emission spectroscopy are introduced. (authors)

  13. Refining Students' Explanations of an Unfamiliar Physical Phenomenon-Microscopic Friction

    Science.gov (United States)

    Corpuz, Edgar De Guzman; Rebello, N. Sanjay

    2017-08-01

    The first phase of this multiphase study involves modeling of college students' thinking of friction at the microscopic level. Diagnostic interviews were conducted with 11 students with different levels of physics backgrounds. A phenomenographic approach of data analysis was used to generate categories of responses which subsequently were used to generate a model of explanation. Most of the students interviewed consistently used mechanical interactions in explaining microscopic friction. According to these students, friction is due to the interlocking or rubbing of atoms. Our data suggest that students' explanations of microscopic friction are predominantly influenced by their macroscopic experiences. In the second phase of the research, teaching experiment was conducted with 18 college students to investigate how students' explanations of microscopic friction can be refined by a series of model-building activities. Data were analyzed using Redish's two-level transfer framework. Our results show that through sequences of hands-on and minds-on activities, including cognitive dissonance and resolution, it is possible to facilitate the refinement of students' explanations of microscopic friction. The activities seemed to be productive in helping students activate associations that refine their ideas about microscopic friction.

  14. In situ ion etching in a scanning electron microscope and its application to the study of dental restorations

    International Nuclear Information System (INIS)

    Dhariwal, R.S.; Ball, P.C.; Marsland, E.A.; Fitch, R.K.

    1978-01-01

    The cylindrical version of the Saddle Field ion source has been water-cooled to eliminate radiation from the source which contributes to the rise in temperature of a specimen undergoing ion bombardment. This has also eliminated the problem of the build-up of black contamination on the anodes which causes a deterioration in the performance within the first hour of operation. In the water-cooled source, smooth conducting films are obtained instead of the black uneven deposit, and this gives extremely stable operation for long periods of time. One of these sources has been incorporated into the specimen stage of a scanning electron microscope to provide a facility for the in situ ion etching of all types of materials. A particular problem of the recurrent failure of dental fillings has been studied in some detail and it is believed that this may be due to a thin bridge of amalgam near the interface with the enamel which is removed during etching, exposing a relatively large gap immediately below. A similar process may occur in the oral environment, where this thin layer can be fractured due to mastication, enabling bacteria to penetrate and thus initiate decay. Work is also being carried out in vivo using replication techniques to try to substantiate these findings. (author)

  15. A practical guide to microscope care and maintenance.

    Science.gov (United States)

    Petrak, Lara J; Waters, Jennifer C

    2014-01-01

    Optimal microscope performance requires regular maintenance and quality control testing. This chapter is a practical guide to microscope care with an emphasis on preventing, identifying and troubleshooting common issues. © 2014 Elsevier Inc. All rights reserved.

  16. Diagnosis and management of microscopic colitis: current perspectives

    Directory of Open Access Journals (Sweden)

    Bohr J

    2014-08-01

    Full Text Available Johan Bohr,1,3 Anna Wickbom,1,3 Agnes Hegedus,2 Nils Nyhlin,1,3 Elisabeth Hultgren Hörnquist,3 Curt Tysk1,3 1Division of Gastroenterology, Department of Medicine, 2Department of Laboratory Medicine/Pathology, Örebro University Hospital, Örebro, 3School of Health and Medical Sciences, Örebro University, Örebro, Sweden Abstract: Collagenous colitis and lymphocytic colitis, together constituting microscopic colitis, are common causes of chronic diarrhea. They are characterized clinically by chronic nonbloody diarrhea and a macroscopically normal colonic mucosa where characteristic histopathological findings are seen. Previously considered rare, they now have emerged as common disorders that need to be considered in the investigation of the patient with chronic diarrhea. The annual incidence of each disorder is five to ten per 100,000 inhabitants, with a peak incidence in 60- to 70-year-old individuals and a predominance of female patients in collagenous colitis. The etiology and pathophysiology are not well understood, and the current view suggests an uncontrolled mucosal immune reaction to various luminal agents in predisposed individuals. Clinical symptoms comprise chronic diarrhea, abdominal pain, fatigue, weight loss, and fecal incontinence that may impair the patient's health-related quality of life. An association is reported with other autoimmune disorders, such as celiac disease, thyroid disorders, diabetes mellitus, and arthritis. The best-documented treatment, both short-term and long-term, is budesonide, which induces clinical remission in up to 80% of patients after 8 weeks' treatment. However, after successful budesonide therapy is ended, recurrence of clinical symptoms is common, and the best possible long-term management deserves further study. The long-term prognosis is good, and the risk of complications, including colonic cancer, is low. We present an update of the epidemiology, pathogenesis, diagnosis, and management of

  17. Occupational concerns associated with regular use of microscope

    OpenAIRE

    Garima Jain; Pushparaja Shetty

    2014-01-01

    Objectives: Microscope work can be strenuous both to the visual system and the musculoskeletal system. Lack of awareness or indifference towards health issues may result in microscope users becoming victim to many occupational hazards. Our objective was to understand the occupational problems associated with regular use of microscope, awareness regarding the hazards, attitude and practice of microscope users towards the problems and preventive strategies. Material and Methods: A questionnaire...

  18. Integration of a high-NA light microscope in a scanning electron microscope.

    Science.gov (United States)

    Zonnevylle, A C; Van Tol, R F C; Liv, N; Narvaez, A C; Effting, A P J; Kruit, P; Hoogenboom, J P

    2013-10-01

    We present an integrated light-electron microscope in which an inverted high-NA objective lens is positioned inside a scanning electron microscope (SEM). The SEM objective lens and the light objective lens have a common axis and focal plane, allowing high-resolution optical microscopy and scanning electron microscopy on the same area of a sample simultaneously. Components for light illumination and detection can be mounted outside the vacuum, enabling flexibility in the construction of the light microscope. The light objective lens can be positioned underneath the SEM objective lens during operation for sub-10 μm alignment of the fields of view of the light and electron microscopes. We demonstrate in situ epifluorescence microscopy in the SEM with a numerical aperture of 1.4 using vacuum-compatible immersion oil. For a 40-nm-diameter fluorescent polymer nanoparticle, an intensity profile with a FWHM of 380 nm is measured whereas the SEM performance is uncompromised. The integrated instrument may offer new possibilities for correlative light and electron microscopy in the life sciences as well as in physics and chemistry. © 2013 The Authors Journal of Microscopy © 2013 Royal Microscopical Society.

  19. The N-salicylidene aniline mesogen: Microscopic and macroscopic properties

    International Nuclear Information System (INIS)

    Nesrullazade, A.

    2004-01-01

    The vast majority of compounds exhibiting Iiquid crystalline phases may be regarded as having a rigid molecular central group with one or two flexible terminal alkyl or alkyloxy chains. The N-saIicyIidene anilines are very interesting and important materials both from fundamental and application points of view. These materials are on the one hand the ligands used to obtain metal containing complexes and on the other hand they are materials having the thermotropic mesomorphism. In this work we present investigations of microscopic and macroscopic properties of the 4-(Octyloxy)-N-(4-hexylphenyl)-2-hydrobenzaIimine (8SA) compound which was synthesized by our group. The 8SA compound shows the smectic C and nematic mesophases. These mesophases are enantiotropic and display specific confocal and schlieren textures, respectively. Thermotropic and thermodynamical properties of the straight and reverse phase transitions between smectic C and nematic mesophases and between nematic mesophase and isotropic liquid have been investigated

  20. Occupational concerns associated with regular use of microscope

    Directory of Open Access Journals (Sweden)

    Garima Jain

    2014-08-01

    Full Text Available Objectives: Microscope work can be strenuous both to the visual system and the musculoskeletal system. Lack of awareness or indifference towards health issues may result in microscope users becoming victim to many occupational hazards. Our objective was to understand the occupational problems associated with regular use of microscope, awareness regarding the hazards, attitude and practice of microscope users towards the problems and preventive strategies. Material and Methods: A questionnaire based survey done on 50 professionals and technicians who used microscope regularly in pathology, microbiology, hematology and cytology laboratories. Results: Sixty two percent of subjects declared that they were suffering from musculoskeletal problems, most common locations being neck and back. Maximum prevalence of musculoskeletal problems was noted in those using microscope for 11–15 years and for more than 30 h/week. Sixty two percent of subjects were aware of workplace ergonomics. Fifty six percent of microscope users took regular short breaks for stretching exercises and 58% took visual breaks every 15–30 min in between microscope use sessions. As many as 94% subjects reported some form of visual problem. Fourty four percent of microscope users felt stressed with long working hours on microscope. Conclusions: The most common occupational concerns of microscope users were musculoskeletal problems of neck and back regions, eye fatigue, aggravation of ametropia, headache, stress due to long working hours and anxiety during or after microscope use. There is an immediate need for increasing awareness about the various occupational hazards and their irreversible effects to prevent them.

  1. Occupational concerns associated with regular use of microscope.

    Science.gov (United States)

    Jain, Garima; Shetty, Pushparaja

    2014-08-01

    Microscope work can be strenuous both to the visual system and the musculoskeletal system. Lack of awareness or indifference towards health issues may result in microscope users becoming victim to many occupational hazards. Our objective was to understand the occupational problems associated with regular use of microscope, awareness regarding the hazards, attitude and practice of microscope users towards the problems and preventive strategies. a questionnaire based survey done on 50 professionals and technicians who used microscope regularly in pathology, microbiology, hematology and cytology laboratories. Sixty two percent of subjects declared that they were suffering from musculoskeletal problems, most common locations being neck and back. Maximum prevalence of musculoskeletal problems was noted in those using microscope for 11-15 years and for more than 30 h/week. Sixty two percent of subjects were aware of workplace ergonomics. Fifty six percent of microscope users took regular short breaks for stretching exercises and 58% took visual breaks every 15-30 min in between microscope use sessions. As many as 94% subjects reported some form of visual problem. Fourty four percent of microscope users felt stressed with long working hours on microscope. The most common occupational concerns of microscope users were musculoskeletal problems of neck and back regions, eye fatigue, aggravation of ametropia, headache, stress due to long working hours and anxiety during or after microscope use. There is an immediate need for increasing awareness about the various occupational hazards and their irreversible effects to prevent them.

  2. The Digital Microscope and Its Image Processing Utility

    Directory of Open Access Journals (Sweden)

    Tri Wahyu Supardi

    2011-12-01

    Full Text Available Many institutions, including high schools, own a large number of analog or ordinary microscopes. These microscopes are used to observe small objects. Unfortunately, object observations on the ordinary microscope require precision and visual acuity of the user. This paper discusses the development of a high-resolution digital microscope from an analog microscope, including the image processing utility, which allows the digital microscope users to capture, store and process the digital images of the object being observed. The proposed microscope is constructed from hardware components that can be easily found in Indonesia. The image processing software is capable of performing brightness adjustment, contrast enhancement, histogram equalization, scaling and cropping. The proposed digital microscope has a maximum magnification of 1600x, and image resolution can be varied from 320x240 pixels up to 2592x1944 pixels. The microscope was tested with various objects with a variety of magnification, and image processing was carried out on the image of the object. The results showed that the digital microscope and its image processing system were capable of enhancing the observed object and other operations in accordance with the user need. The digital microscope has eliminated the need for direct observation by human eye as with the traditional microscope.

  3. 21 CFR 878.4700 - Surgical microscope and accessories.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Surgical microscope and accessories. 878.4700 Section 878.4700 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... microscope and accessories. (a) Identification. A surgical microscope and accessories is an AC-powered device...

  4. Portable ophthalmic microscopes in the Philippines: an overview.

    Science.gov (United States)

    Tan, Anna; Fraser, Clay; Staples, Brian; Mesurier, Richard L; Newland, Henry

    2005-08-01

    Demonstrations were held all over the Philippines to teach local microscope operators basic maintenance skills and troubleshooting for their portable microscopes. Fifteen microscopes were examined and feedback was obtained from 16 microscope operators. The different parameters of the microscope were evaluated as follows: (i) user-friendliness, (ii) demand and availability of technical services and spare parts, (iii) portability and (iv) frequent problems encountered. Some suggestions for improvement are proposed. There was a general satisfaction among the operators with their microscopes; however, there was a lack of technical support services. Most microscopes were portable and the original casing was adequate for transport. Even though most microscopes were functioning, their quality could be improved with maintenance. The three most common problems identified were: mouldy/dirty lenses, expired mould pellets and poor alignment. The portable operating ophthalmic microscope has an important role in the prevention of international blindness. The archaic attitude of sending microscopes to professional technicians for simple maintenance and repair should be abandoned. Instead demonstrations aimed at teaching these skills to local operators and surgeons should be held, in order to improve the technical support available. Different microscope operators can help provide microscope designers with feedback for future improvements. Similar demonstrations could be considered for other countries with a similar scarcity of technical support services.

  5. Designing a curriculum about electron microscope based on ...

    African Journals Online (AJOL)

    Finally, researchers propose 4 objectives and 10 contents about electron microscope learning for undergraduates. The main objects are: An introduction to nanomaterials, a review of optics and lenses, an overview to the optical microscope, an introduction to Electron microscope. Keywords: Nanotechnology; electron ...

  6. Improved Scanners for Microscopic Hyperspectral Imaging

    Science.gov (United States)

    Mao, Chengye

    2009-01-01

    Improved scanners to be incorporated into hyperspectral microscope-based imaging systems have been invented. Heretofore, in microscopic imaging, including spectral imaging, it has been customary to either move the specimen relative to the optical assembly that includes the microscope or else move the entire assembly relative to the specimen. It becomes extremely difficult to control such scanning when submicron translation increments are required, because the high magnification of the microscope enlarges all movements in the specimen image on the focal plane. To overcome this difficulty, in a system based on this invention, no attempt would be made to move either the specimen or the optical assembly. Instead, an objective lens would be moved within the assembly so as to cause translation of the image at the focal plane: the effect would be equivalent to scanning in the focal plane. The upper part of the figure depicts a generic proposed microscope-based hyperspectral imaging system incorporating the invention. The optical assembly of this system would include an objective lens (normally, a microscope objective lens) and a charge-coupled-device (CCD) camera. The objective lens would be mounted on a servomotor-driven translation stage, which would be capable of moving the lens in precisely controlled increments, relative to the camera, parallel to the focal-plane scan axis. The output of the CCD camera would be digitized and fed to a frame grabber in a computer. The computer would store the frame-grabber output for subsequent viewing and/or processing of images. The computer would contain a position-control interface board, through which it would control the servomotor. There are several versions of the invention. An essential feature common to all versions is that the stationary optical subassembly containing the camera would also contain a spatial window, at the focal plane of the objective lens, that would pass only a selected portion of the image. In one version

  7. Lower urinary tract symptoms that predict microscopic pyuria.

    Science.gov (United States)

    Khasriya, Rajvinder; Barcella, William; De Iorio, Maria; Swamy, Sheela; Gill, Kiren; Kupelian, Anthony; Malone-Lee, James

    2017-10-02

    Urinary dipsticks and culture analyses of a mid-stream urine specimen (MSU) at 10 5  cfu ml -1 of a known urinary pathogen are considered the gold standard investigations for diagnosing urinary tract infection (UTI). However, the reliability of these tests has been much criticised and they may mislead. It is now widely accepted that pyuria (≥1 WBC μl -1 ) detected by microscopy of a fresh unspun, unstained specimen of urine is the best biological indicator of UTI available. We aimed to scrutinise the greater potential of symptoms analysis in detecting pyuria and UTI. Lower urinary tract symptom (LUTS) descriptions were collected from patients with chronic lower urinary tract symptoms referred to a tertiary referral unit. The symptoms informed a 39-question inventory, grouped into storage, voiding, stress incontinence and pain symptoms. All questions sought a binary yes or no response. A bespoke software package was developed to collect the data. The study was powered to a sample of at least 1,990 patients, with sufficient power to analyse 39 symptoms in a linear model with an effect size of Cohen's f 2  = 0.02, type 1 error probability = 0.05; and power (1-β); 95% where β is the probability of type 2 error). The inventory was administered to 2,050 female patients between August 2004 and November 2011. The data were collated and the following properties assessed: internal consistency, test-retest reliability, inter-observer reliability, internal responsiveness, external responsiveness, construct validity analysis and a comparison with the International Consultation on Incontinence Modular Questionnaire for female lower urinary tract symptoms (ICIQ-FLUTS). The dependent variable used as a surrogate marker of UTI was microscopic pyuria. An MSU sample was sent for routine culture. The symptoms proved reliable predictors of microscopic pyuria. In particular, voiding symptoms correlated well with microscopic pyuria (χ 2  = 88, df = 1, p symptom inventory

  8. Quantitative imaging with a mobile phone microscope.

    Directory of Open Access Journals (Sweden)

    Arunan Skandarajah

    Full Text Available Use of optical imaging for medical and scientific applications requires accurate quantification of features such as object size, color, and brightness. High pixel density cameras available on modern mobile phones have made photography simple and convenient for consumer applications; however, the camera hardware and software that enables this simplicity can present a barrier to accurate quantification of image data. This issue is exacerbated by automated settings, proprietary image processing algorithms, rapid phone evolution, and the diversity of manufacturers. If mobile phone cameras are to live up to their potential to increase access to healthcare in low-resource settings, limitations of mobile phone-based imaging must be fully understood and addressed with procedures that minimize their effects on image quantification. Here we focus on microscopic optical imaging using a custom mobile phone microscope that is compatible with phones from multiple manufacturers. We demonstrate that quantitative microscopy with micron-scale spatial resolution can be carried out with multiple phones and that image linearity, distortion, and color can be corrected as needed. Using all versions of the iPhone and a selection of Android phones released between 2007 and 2012, we show that phones with greater than 5 MP are capable of nearly diffraction-limited resolution over a broad range of magnifications, including those relevant for single cell imaging. We find that automatic focus, exposure, and color gain standard on mobile phones can degrade image resolution and reduce accuracy of color capture if uncorrected, and we devise procedures to avoid these barriers to quantitative imaging. By accommodating the differences between mobile phone cameras and the scientific cameras, mobile phone microscopes can be reliably used to increase access to quantitative imaging for a variety of medical and scientific applications.

  9. Luttinger liquids from a microscopic perspective

    Science.gov (United States)

    Valiente, Manuel; Phillips, Lawrence G.; Zinner, Nikolaj T.; Öhberg, Patrik

    2017-09-01

    Luttinger liquid theory is a powerful and widely applicable framework for modelling one-dimensional many-body quantum systems. Within this framework, one supposes that the macroscopic behaviour of such systems is entirely determined by two phenomenological parameters, g 2 and g 4. While there exists an intuitive and seemingly sensible physical interpretation of these parameters in terms of the scattering of the system’s constituent particles, g 2 and g 4 are traditionally either fixed by experiment or calculated using heavy-duty numerical techniques, rather than inferred using scattering theory, and for this reason the interpretation remains untested. By applying Luttinger liquid theory in a simple setting, we show that a widely-held and repeatedly-stated belief, namely that the intrabranch terms appearing in Luttinger’s model originate from microscopic intrabranch interactions, is a misconception. We begin with the microscopic model of an interacting one-dimensional, spin-polarized Fermi gas, which we systematically transform into a Luttinger model by introducing an effective interaction, linearizing the dispersion, and renormalizing. By this method, we are able to show that the usual interpretation of g 4 as a measure of intrabranch scattering implies that it must vanish in the dilute limit. Since this runs contrary to conservation of particle number, we conclude that g 4 cannot be related to intrabranch scattering. Rather, we show that g 4 interactions must be included in the effective model in order to compensate for the deleterious effect that introducing an effective interaction has upon the model’s energetics. We explicitly calculate an approximation to this correction for our simple system, and find that it agrees with the value of g 4 found in the literature. We therefore propose a new fermionic Hamiltonian which agrees with the traditional model after bosonisation, but which better reflects the underlying microscopic physics.

  10. Quantitative Imaging with a Mobile Phone Microscope

    Science.gov (United States)

    Skandarajah, Arunan; Reber, Clay D.; Switz, Neil A.; Fletcher, Daniel A.

    2014-01-01

    Use of optical imaging for medical and scientific applications requires accurate quantification of features such as object size, color, and brightness. High pixel density cameras available on modern mobile phones have made photography simple and convenient for consumer applications; however, the camera hardware and software that enables this simplicity can present a barrier to accurate quantification of image data. This issue is exacerbated by automated settings, proprietary image processing algorithms, rapid phone evolution, and the diversity of manufacturers. If mobile phone cameras are to live up to their potential to increase access to healthcare in low-resource settings, limitations of mobile phone–based imaging must be fully understood and addressed with procedures that minimize their effects on image quantification. Here we focus on microscopic optical imaging using a custom mobile phone microscope that is compatible with phones from multiple manufacturers. We demonstrate that quantitative microscopy with micron-scale spatial resolution can be carried out with multiple phones and that image linearity, distortion, and color can be corrected as needed. Using all versions of the iPhone and a selection of Android phones released between 2007 and 2012, we show that phones with greater than 5 MP are capable of nearly diffraction-limited resolution over a broad range of magnifications, including those relevant for single cell imaging. We find that automatic focus, exposure, and color gain standard on mobile phones can degrade image resolution and reduce accuracy of color capture if uncorrected, and we devise procedures to avoid these barriers to quantitative imaging. By accommodating the differences between mobile phone cameras and the scientific cameras, mobile phone microscopes can be reliably used to increase access to quantitative imaging for a variety of medical and scientific applications. PMID:24824072

  11. The therapeutic investigation

    African Journals Online (AJOL)

    In years gone by, the diagnostic process was an intellectual exercise in history taking and examination, then choosing the appropriate investigation. In the Medieval Ages, when. I started practising, we performed X-rays and a few blood tests, and had a centrifuge and microscope in the consulting rooms. There were no ...

  12. Fiber coupled ultrafast scanning tunneling microscope

    DEFF Research Database (Denmark)

    Keil, Ulrich Dieter Felix; Jensen, Jacob Riis; Hvam, Jørn Märcher

    1997-01-01

    We report on a scanning tunneling microscope with a photoconductive gate in the tunneling current circuit. The tunneling tip is attached to a coplanar transmission line with an integrated photoconductive switch. The switch is illuminated through a fiber which is rigidly attached to the switch...... waveguide. The measurements show that the probe works as a transient voltage detector in contact and a capacitively coupled transient field detector in tunneling mode. We do not measure the transient voltage change in the ohmic tunneling current. In this sense, the spatial resolution for propagating...

  13. Microscopic optoelectronic defectoscopy of solar cells

    Directory of Open Access Journals (Sweden)

    Dallaeva D.

    2013-05-01

    Full Text Available Scanning probe microscopes are powerful tool for micro- or nanoscale diagnostics of defects in crystalline silicon solar cells. Solar cell is a large p-n junction semiconductor device. Its quality is strongly damaged by the presence of defects. If the cell works under low reverse-biased voltage, defects emit a light in visible range. The suggested method combines three different measurements: electric noise measurement, local topography and near-field optical beam induced current and thus provides more complex information. To prove its feasibility, we have selected one defect (truncated pyramid in the sample, which emitted light under low reverse-biased voltage.

  14. Ponderomotive phase plate for transmission electron microscopes

    Science.gov (United States)

    Reed, Bryan W [Livermore, CA

    2012-07-10

    A ponderomotive phase plate system and method for controllably producing highly tunable phase contrast transfer functions in a transmission electron microscope (TEM) for high resolution and biological phase contrast imaging. The system and method includes a laser source and a beam transport system to produce a focused laser crossover as a phase plate, so that a ponderomotive potential of the focused laser crossover produces a scattering-angle-dependent phase shift in the electrons of the post-sample electron beam corresponding to a desired phase contrast transfer function.

  15. Hardware for digitally controlled scanned probe microscopes

    OpenAIRE

    Clark, S. M.; Baselt, D. R.; Spence, C. F.; Youngquist, M. G.; Baldeschwieler, J. D.

    1992-01-01

    The design and implementation of a flexible and modular digital control and data acquisition system for scanned probe microscopes (SPMs) is presented. The measured performance of the system shows it to be capable of 14-bit data acquisition at a 100-kHz rate and a full 18-bit output resolution resulting in less than 0.02-Å rms position noise while maintaining a scan range in excess of 1 µm in both the X and Y dimensions. This level of performance achieves the goal of making the noise of the mi...

  16. Imaging optical scattering of butterfly wing scales with a microscope.

    Science.gov (United States)

    Fu, Jinxin; Yoon, Beom-Jin; Park, Jung Ok; Srinivasarao, Mohan

    2017-08-06

    A new optical method is proposed to investigate the reflectance of structurally coloured objects, such as Morpho butterfly wing scales and cholesteric liquid crystals. Using a reflected-light microscope and a digital single-lens reflex (DSLR) camera, we have successfully measured the two-dimensional reflection pattern of individual wing scales of Morpho butterflies. We demonstrate that this method enables us to measure the bidirectional reflectance distribution function (BRDF). The scattering image observed in the back focal plane of the objective is projected onto the camera sensor by inserting a Bertrand lens in the optical path of the microscope. With monochromatic light illumination, we quantify the angle-dependent reflectance spectra from the wing scales of Morpho rhetenor by retrieving the raw signal from the digital camera sensor. We also demonstrate that the polarization-dependent reflection of individual wing scales is readily observed using this method, using the individual wing scales of Morpho cypris . In an effort to show the generality of the method, we used a chiral nematic fluid to illustrate the angle-dependent reflectance as seen by this method.

  17. Microscopic assessment of bone toughness using scratch tests

    Directory of Open Access Journals (Sweden)

    Amrita Kataruka

    2017-06-01

    Full Text Available Bone is a composite material with five distinct structural levels: collagen molecules, mineralized collagen fibrils, lamellae, osteon and whole bone. However, most fracture testing methods have been limited to the macroscopic scale and there is a need for advanced characterization methods to assess toughness at the osteon level and below. The goal of this investigation is to present a novel framework to measure the fracture properties of bone at the microscopic scale using scratch testing. A rigorous experimental protocol is articulated and applied to examine cortical bone specimens from porcine femurs. The observed fracture behavior is very complex: we observe a strong anisotropy of the response with toughening mechanisms and a competition between plastic flow and brittle fracture. The challenge consists then in applying nonlinear fracture mechanics methods such as the J-integral or the energetic Size Effect Law to quantify the fracture toughness in a rigorous fashion. Our result suggests that mixed-mode fracture is instrumental in determining the fracture resistance. There is also a pronounced coupling between fracture and elasticity. Our methodology opens the door to fracture assessment at multiple structural levels, microscopic and potentially nanometer length scale, due to the scalability of scratch tests.

  18. Distributed microscopic actuation analysis of deformable plate membrane mirrors

    Science.gov (United States)

    Lu, Yifan; Yue, Honghao; Deng, Zongquan; Tzou, Hornsen

    2018-02-01

    To further reduce the areal density of optical mirrors used in space telescopes and other space-borne optical structures, the concept of flexible membrane deformable mirror has been proposed. Because of their high flexibility, poor stiffness and low damping properties, environmental excitations such as orbital maneuver, path changing, and non-uniform heating may induce unexpected vibrations and thus reduce working performance. Therefore, active vibration control is essential for these membrane mirrors. In this paper, two different mirror models, i.e., the plate membrane model and pure membrane model, are studied respectively. In order to investigate the modal vibration characteristics of the mirror, a piezoelectric layer is fully laminated on its non-reflective side to serve as actuators. Dynamic equations of the mirror laminated with piezoelectric actuators are presented first. Then, the actuator induced modal control force is defined. When the actuator area shrinks to infinitesimal, the expressions of microscopic local modal control force and its two components are obtained to predict the spatial microscopic actuation behavior of the mirror. Different membrane pretension forces are also applied to reveal the tension effects on the actuation of the mirror. Analyses indicate that the spatial distribution of modal micro-control forces is exactly the same with the sensing signals distribution of the mirror, which provides crucial guidelines for optimal actuator placement of membrane deformable mirrors.

  19. The interference Linnik type microscope (IM) developed at Inmetro

    International Nuclear Information System (INIS)

    Malinovski, I; Couceiro, I B; Lima, M S; França, R S; Von der Weid, J P

    2015-01-01

    The interference Linnik type microscope was developed and it design was modernized to provide high resolution nanometrology facility. This microscope can perform length measurement directly relative to wavelength standards such as the frequency stabilized lasers. Thus, one can use interference microscope for primary calibration of the step heights. These step heights can be used to calibrate vertical axis of the other instruments like optical coherence tomography, atomic force microscope, confocal microscope, etc. In all cases the traceability to the National Institute of Metrology, Quality and Technology length primary standards was attempted to be established

  20. [Remote Slit Lamp Microscope Consultation System Based on Web].

    Science.gov (United States)

    Chen, Junfa; Zhuo, Yong; Liu, Zuguo; Chen, Yanping

    2015-11-01

    To realize the remote operation of the slit lamp microscope for department of ophthalmology consultation, and visual display the real-time status of remote slit lamp microscope, a remote slit lamp microscope consultation system based on B/S structure is designed and implemented. Through framing the slit lamp microscope on the website system, the realtime acquisition and transmission of remote control and image data is realized. The three dimensional model of the slit lamp microscope is established and rendered on the web by using WebGL technology. The practical application results can well show the real-time interactive of the remote consultation system.

  1. Adiabatically describing rare earths using microscopic deformations

    Science.gov (United States)

    Nobre, Gustavo; Dupuis, Marc; Herman, Michal; Brown, David

    2017-09-01

    Recent works showed that reactions on well-deformed nuclei in the rare-earth region are very well described by an adiabatic method. This assumes a spherical optical potential (OP) accounting for non-rotational degrees of freedom while the deformed configuration is described by couplings to states of the g.s. rotational band. This method has, apart from the global OP, only the deformation parameters as inputs, with no additional fit- ted variables. For this reason, it has only been applied to nuclei with well-measured deformations. With the new computational capabilities, microscopic large-scale calculations of deformation parameters within the HFB method based on the D1S Gogny force are available in the literature. We propose to use such microscopic deformations in our adi- abatic method, allowing us to reproduce the cross sections agreements observed in stable nuclei, and to reliably extend this description to nuclei far from stability, describing the whole rare-earth region. Since all cross sections, such as capture and charge exchange, strongly depend on the correct calculation of absorption from the incident channel (from direct reaction mechanisms), this approach significantly improves the accuracy of cross sections and transitions relevant to astrophysical studies. The work at BNL was sponsored by the Office of Nuclear Physics, Office of Science of the US Department of Energy, under Contract No. DE-AC02-98CH10886 with Brookhaven Science Associates, LLC.

  2. Excitation-scanning hyperspectral imaging microscope

    Science.gov (United States)

    Favreau, Peter F.; Hernandez, Clarissa; Heaster, Tiffany; Alvarez, Diego F.; Rich, Thomas C.; Prabhat, Prashant; Leavesley, Silas J.

    2014-01-01

    Abstract. Hyperspectral imaging is a versatile tool that has recently been applied to a variety of biomedical applications, notably live-cell and whole-tissue signaling. Traditional hyperspectral imaging approaches filter the fluorescence emission over a broad wavelength range while exciting at a single band. However, these emission-scanning approaches have shown reduced sensitivity due to light attenuation from spectral filtering. Consequently, emission scanning has limited applicability for time-sensitive studies and photosensitive applications. In this work, we have developed an excitation-scanning hyperspectral imaging microscope that overcomes these limitations by providing high transmission with short acquisition times. This is achieved by filtering the fluorescence excitation rather than the emission. We tested the efficacy of the excitation-scanning microscope in a side-by-side comparison with emission scanning for detection of green fluorescent protein (GFP)-expressing endothelial cells in highly autofluorescent lung tissue. Excitation scanning provided higher signal-to-noise characteristics, as well as shorter acquisition times (300  ms/wavelength band with excitation scanning versus 3  s/wavelength band with emission scanning). Excitation scanning also provided higher delineation of nuclear and cell borders, and increased identification of GFP regions in highly autofluorescent tissue. These results demonstrate excitation scanning has utility in a wide range of time-dependent and photosensitive applications. PMID:24727909

  3. A microscopic study of nuclear deformed states

    International Nuclear Information System (INIS)

    Jarrio, M.M.

    1996-06-01

    Traditional models of collective nuclear rotations are phenomenological in nature, relying on a relatively small number of shape variables to characterize the deformation of the nuclear surface. Although generally successful, such models have a number of drawbacks. In particular, the fermionic many-body nature of the nucleus is ignored, and hence such models cannot adequately describe the intrinsic matter flows within the nucleus. Recently, group theoretical techniques have led to algebraic descriptions of nuclear rotation which are microscopically realizable. That is, such models can describe the collective rotation of the nucleus as a whole in terms of the coordinates and momenta of individual nucleons. This thesis describes two such models - the SU(3) model and the Sp(3,R) model - in some detail. Expressions are obtained for physical observables relevant to rotational nuclei, and comparison is made with experimental data for even-mass nuclei. A particular objective is the identification of those representations which play a dominant role in the physical state of the nucleus, and the interpretation of these states in microscopic shell-model terms. Finally, spin and intrinsic single-particle degrees of freedom are included in the SU(3) and Sp(3,R) models, and a prescription is formulated for an eventual comparison with experimental data for odd-mass nuclei

  4. A LEGO Mindstorms Brewster angle microscope

    Science.gov (United States)

    Fernsler, Jonathan; Nguyen, Vincent; Wallum, Alison; Benz, Nicholas; Hamlin, Matthew; Pilgram, Jessica; Vanderpoel, Hunter; Lau, Ryan

    2017-09-01

    A Brewster Angle Microscope (BAM) built from a LEGO Mindstorms kit, additional LEGO bricks, and several standard optics components, is described. The BAM was built as part of an undergraduate senior project and was designed, calibrated, and used to image phospholipid, cholesterol, soap, and oil films on the surface of water. A BAM uses p-polarized laser light reflected off a surface at the Brewster angle, which ideally yields zero reflectivity. When a film of different refractive index is added to the surface a small amount of light is reflected, which can be imaged in a microscope camera. Films of only one molecule (approximately 1 nm) thick, a monolayer, can be observed easily in the BAM. The BAM was used in a junior-level Physical Chemistry class to observe phase transitions of a monolayer and the collapse of a monolayer deposited on the water surface in a Langmuir trough. Using a photometric calculation, students observed a change in thickness of a monolayer during a phase transition of 7 Å, which was accurate to within 1 Å of the value determined by more advanced methods. As supplementary material, we provide a detailed manual on how to build the BAM, software to control the BAM and camera, and image processing software.

  5. Statistical mechanics of microscopically thin thermalized shells

    Science.gov (United States)

    Kosmrlj, Andrej

    Recent explosion in fabrication of microscopically thin free standing structures made from graphene and other two-dimensional materials has led to a renewed interest in the mechanics of such structures in presence of thermal fluctuations. Since late 1980s it has been known that for flat solid sheets thermal fluctuations effectively increase the bending rigidity and reduce the bulk and shear moduli in a scale-dependent fashion. However, much is still unknown about the mechanics of thermalized flat sheets of complex geometries and about the mechanics of thermalized shells with non-zero background curvature. In this talk I will present recent development in the mechanics of thermalized ribbons, spherical shells and cylindrical tubes. Long ribbons are found to behave like hybrids between flat sheets with renormalized elastic constants and semi-flexible polymers, and these results can be used to predict the mechanics of graphene kirigami structures. Contrary to the anticipated behavior for ribbons, the non-zero background curvature of shells leads to remarkable novel phenomena. In shells, thermal fluctuations effectively generate negative surface tension, which can significantly reduce the critical buckling pressure for spherical shells and the critical axial load for cylindrical tubes. For large shells this thermally generated load becomes big enough to spontaneously crush spherical shells and cylindrical tubes even in the absence of external loads. I will comment on the relevance for crushing of microscopic shells (viral capsids, bacteria, microcapsules) due to osmotic shocks and for crushing of nanotubes.

  6. The poor man's scanning force microscope

    International Nuclear Information System (INIS)

    Guerra-Vela, Claudio; Zypman, Fredy R.

    2002-01-01

    The Macroscope (Zypman F R and Guerra-Vela C 2001 Eur. J. Phys. 22 17-30), an educational large-scale version of a scanning force microscope's cantilever-tip system, is used in the presence of nonlinear forces. This paper presents quantitative experimental evidence confirming the validity of the beam model (BM) (Eppel S J, Todd B A and Zypman F R 2000 Materials Issues and Modeling for Device Nanofabrication ed L Merhari et al (Pittsburgh, PA: Materials Research Society) pp 584, 189) as a proper reconstruction algorithm. As a teaching laboratory experiment, the force measurements are first done directly with a variety of dynamometer-like setups. Subsequently, the measurements are performed indirectly with the Macroscope from the cantilever resonant frequency shifts and the BM algorithm. Two central results of this work lie in its ability to compare forces obtained by traditional algorithms with known forces, and to illustrate in a hands-on fashion the principles behind the working of a scanning force microscope. (author)

  7. Microscopic and thermodynamic properties of dense semiclassical partially ionized hydrogen plasma

    Energy Technology Data Exchange (ETDEWEB)

    Ramazanov, T S; Dzhumagulova, K N; Gabdullin, M T [IETP, Al-Farabi Kazakh National University, 96a, Tole Bi St, Almaty, 050012 (Kazakhstan)

    2006-04-28

    Microscopic and thermodynamic properties of dense semiclassical partially ionized hydrogen plasma were investigated on the basis of pseudopotential models. Radial distribution functions (RDF) of particles were obtained using a system of the Ornstein-Zernike integral equations. The corrections to internal energy and the equation of state were calculated using RDF.

  8. An Antique Microscope Slide Brings the Thrill of Discovery into a Contemporary Biology Classroom

    Science.gov (United States)

    Reiser, Frank

    2012-01-01

    The discovery of a Victorian-era microscope slide titled "Grouped Flower Seeds" began an investigation into the scientific and historical background of the antique slide to develop its usefulness as a multidisciplinary tool for PowerPoint presentations usable in contemporary biology classrooms, particularly large-enrollment sections. The resultant…

  9. Adulteration of honey : relation between microscopic analysis and delta C-13 measurements

    NARCIS (Netherlands)

    Kerkvliet, JD; Meijer, HAJ

    2000-01-01

    Upon routine microscopic analysis of some honey samples, parenchyma cells, single rings of ring vessels and epidermal cells are found. These cells originate from the sugar cane stem. We investigated whether there was a relation between these plant fragments and the delta C-13 value of honey. 17

  10. Anthropometry and pancreatic cancer risk: An illustration of the importance of microscopic verification

    NARCIS (Netherlands)

    Verhage, B.A.J.; Schouten, L.J.; Goldbohm, R.A.; Brandt, P.A. van den

    2007-01-01

    Using data collected of a large population-based cohort study, we studied the association between anthropometric factors and the risk of pancreatic cancer. Furthermore, we investigated whether these associations differ among microscopically confirmed pancreatic cancer (MCPC) cases and non-MCPC

  11. High resolution, large through-put x-ray microscopes for target diagnostics

    International Nuclear Information System (INIS)

    Palmieri, T.M.; Boyle, M.J.; Ahlstrom, H.G.; Monjes, J.A.

    1975-01-01

    The imaging properties and design principles for an axisymmetric x-ray microscope using a hyperboloid surface preceding an ellipsoidal reflecting surface are discussed. The results of a design study investigating the off-axis resolution of x-ray microcopes are presented

  12. Microscopic Origin of Heisenberg and Non-Heisenberg Exchange Interactions in Ferromagnetic bcc Fe

    NARCIS (Netherlands)

    Kvashnin, Y.O.; Cardias, R.; Szilva, A.; Di Marco, I.; Katsnelson, M.I.; Lichtenstein, A.I.; Nordstrom, L.; Klautau, A.B.; Eriksson, O.

    2016-01-01

    By means of first principles calculations, we investigate the nature of exchange coupling in ferromagnetic bcc Fe on a microscopic level. Analyzing the basic electronic structure reveals a drastic difference between the 3d orbitals of E-g and T-2g symmetries. The latter ones define the shape of the

  13. Isocentric rotational performance of the Elekta Precise Table studied using a USB-microscope

    DEFF Research Database (Denmark)

    Riis, Hans L; Zimmermann, Sune J; Riis, Poul

    2010-01-01

    The isocentric three-dimensional performance of the Elekta Precise Table was investigated. A pointer was attached to the radiation head of the accelerator and positioned at the geometric rotational axis of the head. A USB-microscope was mounted on the treatment tabletop to measure the table...

  14. Transient measurements with an ultrafast scanning tunneling microscope

    DEFF Research Database (Denmark)

    Keil, Ulrich Dieter Felix; Jensen, Jacob Riis; Hvam, Jørn Märcher

    1998-01-01

    We use a photoconductively gated ultrafast scanning tunneling microscope to resolve laser-induced transients on transmission lines and photoconductors. The photoconductive switch on the tunneling probe is illuminated through a rigidly attached fiber. The use of the fiber enables us to scan across...... the transmission line while the change in delay time between pump beam (on the sample) and probe beam (on the probe) provides the temporal information. The investigated photoconductor sample is a low-temperature-grown GaAs layer placed on a sapphire substrate with a thin, semitransparent gold layer. In tunneling...... mode the probe is sensitive to laser-induced field changes in the semiconductor layer. Laser-induced transient signals of 2.2 ps widths are detected. As for the transmission lines, the signals can be explained by a capacitive coupling across the tunneling gap....

  15. Evaluation of microscopic hematuria: a critical review and proposed algorithm.

    Science.gov (United States)

    Niemi, Matthew A; Cohen, Robert A

    2015-07-01

    Microscopic hematuria (MH), often discovered incidentally, has many causes, including benign processes, kidney disease, and genitourinary malignancy. The clinician, therefore, must decide how intensively to investigate the source of MH and select which tests to order and referrals to make, aiming not to overlook serious conditions while simultaneously avoiding unnecessary tests. Existing professional guidelines for the evaluation of MH are largely based on expert opinion and have weak evidence bases. Existing data demonstrate associations between isolated MH and various diseases in certain populations, and these associations serve as the basis for our proposed approach to the evaluation of MH. Various areas of ongoing uncertainty regarding the appropriate evaluation should be the basis for ongoing research. Copyright © 2015 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

  16. Microscopic single-crystal refractometry as a function of wavelength

    International Nuclear Information System (INIS)

    DeLoach, L.D.

    1994-01-01

    The refractive indices of crystal fragments 50--200 μm in size can be measured for light wavelengths between 365 and 1100 nm with a spindle-stage refractometer. Established methods from optical crystallograpy are used to orient a crystal on the microscope spindle stage and then to match its refractive index to an immersion fluid. The refractive index of the fluid for the wavelength of light and matching temperature is determined by comparison of a reference crystal on a second spindle axis with the fluid under the match conditions. Investigations of new nonlinear-optical crystals admirably demonstrate the advantages of measuring the refractive index to ± 0.0004 in small single crystals

  17. Electric field stimulation setup for photoemission electron microscopes.

    Science.gov (United States)

    Buzzi, M; Vaz, C A F; Raabe, J; Nolting, F

    2015-08-01

    Manipulating magnetisation by the application of an electric field in magnetoelectric multiferroics represents a timely issue due to the potential applications in low power electronics and the novel physics involved. Thanks to its element sensitivity and high spatial resolution, X-ray photoemission electron microscopy is a uniquely suited technique for the investigation of magnetoelectric coupling in multiferroic materials. In this work, we present a setup that allows for the application of in situ electric and magnetic fields while the sample is analysed in the microscope. As an example of the performances of the setup, we present measurements on Ni/Pb(Mg(0.66)Nb(0.33))O3-PbTiO3 and La(0.7)Sr(0.3)MnO3/PMN-PT artificial multiferroic nanostructures.

  18. Comparison microscope identification of a cheese bitemark: a case report.

    Science.gov (United States)

    Bernitz, H; Kloppers, B A

    2002-06-01

    Police investigating the murder of a farmer recovered a piece of cheese containing bite- marks. The local dental practitioner used white plaster to make casts of the bitemarks in the cheese and also of the teeth of three suspects. The cheese specimen was retained by the police and seven months later the case was referred to the Forensic Odontology Unit at the University of Pretoria where a silicone rubber cast of the bitemarks in the cheese was made. A lack of concordant features present in a conventional pattern-associated comparison was overcome with the aid of a Leica DMC comparison microscope. Individual features observed under 6.3x magnification aided in the positive identification of the suspect, who when confronted with the evidence, admitted guilt at his first court appearance.

  19. Microscopic Origin of Interfacial Dzyaloshinskii-Moriya Interaction

    KAUST Repository

    Kim, Sanghoon

    2017-04-10

    Chiral spin textures at the interface between ferromagnetic and heavy nonmagnetic metals, such as Neel-type domain walls and skyrmions, have been studied intensively because of their great potential for future nanomagnetic devices. The Dyzaloshinskii-Moriya interaction (DMI) is an essential phenomenon for the formation of such chiral spin textures. In spite of recent theoretical progress aiming at understanding the microscopic origin of the DMI, an experimental investigation unravelling the physics at stake is still required. Here, we experimentally demonstrate the close correlation of the DMI with the anisotropy of the orbital magnetic moment and with the magnetic dipole moment of the ferromagnetic metal. The density functional theory and the tight-binding model calculations reveal that asymmetric electron occupation in orbitals gives rise to this correlation.

  20. Fabrication, Cleaning, and Filtering of Microscopic Droplet Beam Nozzles

    Science.gov (United States)

    Warner, J.; Hunter, M.; Weierstall, U.; Spence, J. C. H.; Doak, R. B.

    2006-10-01

    Structure determination of proteins is a subject of intense current interest. Most relevant is a protein's native conformation, which generally requires it be immersed in water (if water-soluble) or a lipid jacket (if a membrane protein). Emerging schemes of serial protein diffraction propose to embed proteins in microscopic water droplets (membrane proteins encased in a detergent micelle) and pass these in vacuum through an x-ray or electron beam. Droplet diameters of tested, with and without sonication and both before and after the nozzle tip was formed. Flame burnishing was employed to smooth and clean the nozzles. In situ formation of silicate filter frits was investigated. Still, only about 30% of the 4 μm nozzles would run without clogging. An alternative to solid convergent nozzles will be described.

  1. Microscopic to macroscopic depletion model development for FORMOSA-P

    International Nuclear Information System (INIS)

    Noh, J.M.; Turinsky, P.J.; Sarsour, H.N.

    1996-01-01

    Microscopic depletion has been gaining popularity with regard to employment in reactor core nodal calculations, mainly attributed to the superiority of microscopic depletion in treating spectral history effects during depletion. Another trend is the employment of loading pattern optimization computer codes in support of reload core design. Use of such optimization codes has significantly reduced design efforts to optimize reload core loading patterns associated with increasingly complicated lattice designs. A microscopic depletion model has been developed for the FORMOSA-P pressurized water reactor (PWR) loading pattern optimization code. This was done for both fidelity improvements and to make FORMOSA-P compatible with microscopic-based nuclear design methods. Needless to say, microscopic depletion requires more computational effort compared with macroscopic depletion. This implies that microscopic depletion may be computationally restrictive if employed during the loading pattern optimization calculation because many loading patterns are examined during the course of an optimization search. Therefore, the microscopic depletion model developed here uses combined models of microscopic and macroscopic depletion. This is done by first performing microscopic depletions for a subset of possible loading patterns from which 'collapsed' macroscopic cross sections are obtained. The collapsed macroscopic cross sections inherently incorporate spectral history effects. Subsequently, the optimization calculations are done using the collapsed macroscopic cross sections. Using this approach allows maintenance of microscopic depletion level accuracy without substantial additional computing resources

  2. Microscopic origin of volume modulus inflation

    Energy Technology Data Exchange (ETDEWEB)

    Cicoli, Michele [ICTP, Strada Costiera 11, Trieste 34014 (Italy); Dipartimento di Fisica e Astronomia, Università di Bologna, via Irnerio 46, 40126 Bologna (Italy); INFN, Sezione di Bologna, via Irnerio 46, 40126 Bologna (Italy); Muia, Francesco [Dipartimento di Fisica e Astronomia, Università di Bologna, via Irnerio 46, 40126 Bologna (Italy); INFN, Sezione di Bologna, via Irnerio 46, 40126 Bologna (Italy); Pedro, Francisco Gil [Departamento de Fisica Teórica UAM and Instituto de Fisica Teórica UAM/CSIC, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid (Spain)

    2015-12-21

    High-scale string inflationary models are in well-known tension with low-energy supersymmetry. A promising solution involves models where the inflaton is the volume of the extra dimensions so that the gravitino mass relaxes from large values during inflation to smaller values today. We describe a possible microscopic origin of the scalar potential of volume modulus inflation by exploiting non-perturbative effects, string loop and higher derivative perturbative corrections to the supergravity effective action together with contributions from anti-branes and charged hidden matter fields. We also analyse the relation between the size of the flux superpotential and the position of the late-time minimum and the inflection point around which inflation takes place. We perform a detailed study of the inflationary dynamics for a single modulus and a two moduli case where we also analyse the sensitivity of the cosmological observables on the choice of initial conditions.

  3. System for optical sorting of microscopic objects

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention relates to a system for optical sorting of microscopic objects and corresponding method. An optical detection system (52) is capable of determining the positions of said first and/or said second objects. One or more force transfer units (200, 205, 210, 215) are placed...... in a first reservoir, the one or more force units being suitable for optical momentum transfer. An electromagnetic radiation source (42) yields a radiation beam (31, 32) capable of optically displacing the force transfer units from one position to another within the first reservoir (1R). The force transfer...... units are displaced from positions away from the first objects to positions close to the first objects, and then displacing the first objects via a contact force (300) between the first objects and the force transfer units facilitates an optical sorting of the first objects and the second objects....

  4. Microscopic polyangiitis secondary to silica exposure.

    Science.gov (United States)

    Vega Miranda, Juliana; Pinto Peñaranda, Luis Fernando; Márquez Hernández, Javier Darío; Velásquez Franco, Carlos Jaime

    2014-01-01

    There is sufficient evidence of the capacity of silica to induce autoimmunity in patients with some type of genetic susceptibility. There are several autoimmune diseases related to this exposure (rheumatoid arthritis, Sjögren's syndrome, sarcoidosis, systemic sclerosis). Nodular silicosis (clinical expression of this exposure in lungs) generates apoptosis, inflammation, loss of tolerance and a respiratory burst. There is evidence that relates silica with induction of antineutrophil cytoplasmic antibodies, but, until it is better explained, the reports of systemic vasculitis secondary to silica exposure are inconclusive. We describe a case of a patient with a history of occupational exposure to silica who developed microscopic polyangiitis. Copyright © 2013 Elsevier España, S.L. All rights reserved.

  5. The resolution limit of scanning capacitance microscopes

    CERN Document Server

    Lany, S

    2003-01-01

    The contrast formation and the achievable lateral resolution of a scanning capacitance microscope have been simulated using the finite element method. On conducting surfaces, a resolution of about 2 nm is expected with probes with about 5-10 nm radius of curvature. At smaller radii, the resolution degrades due to the decrease of the local contribution to the integral capacitance sensed by the probe. The lateral resolution is less affected by the radius of the tip than by the tip-to-conducting base distance, though sharper tips produce higher contrast. With a tip radius of approximately 25 nm, resolution of features 5 nm in diameter has been achieved on gold-coated silicon.

  6. The Scanning TMR Microscope for Biosensor Applications

    Directory of Open Access Journals (Sweden)

    Kunal N. Vyas

    2015-04-01

    Full Text Available We present a novel tunnel magnetoresistance (TMR scanning microscopeset-up capable of quantitatively imaging the magnetic stray field patterns of micron-sizedelements in 3D. By incorporating an Anderson loop measurement circuit for impedancematching, we are able to detect magnetoresistance changes of as little as 0.006%/Oe. By 3Drastering a mounted TMR sensor over our magnetic barcodes, we are able to characterisethe complex domain structures by displaying the real component, the amplitude and thephase of the sensor’s impedance. The modular design, incorporating a TMR sensor withan optical microscope, renders this set-up a versatile platform for studying and imagingimmobilised magnetic carriers and barcodes currently employed in biosensor platforms,magnetotactic bacteria and other complex magnetic domain structures of micron-sizedentities. The quantitative nature of the instrument and its ability to produce vector maps ofmagnetic stray fields has the potential to provide significant advantages over other commonlyused scanning magnetometry techniques.

  7. Performance of the SRRC scanning photoelectron microscope

    CERN Document Server

    Hong, I H; Yin, G C; Wei, D H; Juang, J M; Dann, T E; Klauser, R; Chuang, T J; Chen, C T; Tsang, K L

    2001-01-01

    A scanning photoelectron microscope has been constructed at SRRC. This SPEM system consists primarily of a Fresnel zone plate (ZP) with an order-selection aperture, a flexure scanning stage, a hemispherical electron analyzer, and sample/ZP insertion system. The flexure stage is used to scan the sample. A hemispherical analyzer with Omni V lens and a 16-channel multichannel detector (MCD) is used to collect photoelectrons. A set of 16 photoelectron images at different kinetic energies can be simultaneously acquired in one single scan. The data acquisition system is designed to collect up to 32 images concurrently, including 16 MCD signals, total electron yield and transmitted photon flux. The design and some initial test results of this SPEM station are presented and discussed.

  8. Performance of the SRRC scanning photoelectron microscope

    International Nuclear Information System (INIS)

    Hong, I.-H.; Lee, T.-H.; Yin, G.-C.; Wei, D.-H.; Juang, J.-M.; Dann, T.-E.; Klauser, R.; Chuang, T.J.; Chen, C.T.; Tsang, K.-L.

    2001-01-01

    A scanning photoelectron microscope has been constructed at SRRC. This SPEM system consists primarily of a Fresnel zone plate (ZP) with an order-selection aperture, a flexure scanning stage, a hemispherical electron analyzer, and sample/ZP insertion system. The flexure stage is used to scan the sample. A hemispherical analyzer with Omni V lens and a 16-channel multichannel detector (MCD) is used to collect photoelectrons. A set of 16 photoelectron images at different kinetic energies can be simultaneously acquired in one single scan. The data acquisition system is designed to collect up to 32 images concurrently, including 16 MCD signals, total electron yield and transmitted photon flux. The design and some initial test results of this SPEM station are presented and discussed

  9. Microscopic origin of volume modulus inflation

    Science.gov (United States)

    Cicoli, Michele; Muia, Francesco; Gil Pedro, Francisco

    2015-12-01

    High-scale string inflationary models are in well-known tension with low-energy supersymmetry. A promising solution involves models where the inflaton is the volume of the extra dimensions so that the gravitino mass relaxes from large values during inflation to smaller values today. We describe a possible microscopic origin of the scalar potential of volume modulus inflation by exploiting non-perturbative effects, string loop and higher derivative perturbative corrections to the supergravity effective action together with contributions from anti-branes and charged hidden matter fields. We also analyse the relation between the size of the flux superpotential and the position of the late-time minimum and the inflection point around which inflation takes place. We perform a detailed study of the inflationary dynamics for a single modulus and a two moduli case where we also analyse the sensitivity of the cosmological observables on the choice of initial conditions.

  10. In-Situ Microprobe Observations of Dispersed Oil with Low-Temperature Low-Vacuum Scanning Electron Microscope

    International Nuclear Information System (INIS)

    Mohsen, H.T.

    2010-01-01

    A low cost cryostat stage from high heat capacity material is designed and constructed, in attempt to apply size distribution techniques for examination of oil dispersions. Different materials were tested according to their heat capacity to keep the liquid under investigation in frozen state as long as possible during the introduction of the cryostat stage to the low-vacuum scanning electron microscope. Different concentrations of non ionic surfactant were added to artificially contaminated with 10000 ppm Balayeam base oil in 3.5 % saline water, where oil and dispersing liquid have been added and shacked well to be investigated under the microscope as fine frozen droplets. The efficiency of dispersion was examined using low temperature low-vacuum scanning electron microscope. The shape and size distributions of freeze oil droplets were studied by digital imaging processing technique in conjunction with scanning electron microscope counting method. Also elemental concentration of oil droplets was analyzed.

  11. Scanning SQUID microscope with an in-situ magnetization/demagnetization field for geological samples

    Science.gov (United States)

    Du, Junwei; Liu, Xiaohong; Qin, Huafeng; Wei, Zhao; Kong, Xiangyang; Liu, Qingsong; Song, Tao

    2018-04-01

    Magnetic properties of rocks are crucial for paleo-, rock-, environmental-magnetism, and magnetic material sciences. Conventional rock magnetometers deal with bulk properties of samples, whereas scanning microscope can map the distribution of remanent magnetization. In this study, a new scanning microscope based on a low-temperature DC superconducting quantum interference device (SQUID) equipped with an in-situ magnetization/demagnetization device was developed. To realize the combination of sensitive instrument as SQUID with high magnetizing/demagnetizing fields, the pick-up coil, the magnetization/demagnetization coils and the measurement mode of the system were optimized. The new microscope has a field sensitivity of 250 pT/√Hz at a coil-to-sample spacing of ∼350 μm, and high magnetization (0-1 T)/ demagnetization (0-300 mT, 400 Hz) functions. With this microscope, isothermal remanent magnetization (IRM) acquisition and the according alternating field (AF) demagnetization curves can be obtained for each point without transferring samples between different procedures, which could result in position deviation, waste of time, and other interferences. The newly-designed SQUID microscope, thus, can be used to investigate the rock magnetic properties of samples at a micro-area scale, and has a great potential to be an efficient tool in paleomagnetism, rock magnetism, and magnetic material studies.

  12. An optoelectronic system for trans microscopic registration of oscillatory contraction phenomena

    International Nuclear Information System (INIS)

    Shraideh, A. Z.; Salman, Y. M.

    1998-01-01

    A trans microscope registration electronic system using cadmium sulphide photoconductive cell as light dependent resistor is described. This photocell has a spectral response similar to that of the human eye and enable registration of cellular motion phenomena along with their microscopic observation. The photocell is of the type ORP 12 which when replacing one of the oculars of the light microscope, can register changes in light intensity caused due to any movement of the studied living objects. The large diameter sensing element allows registration of full size of the contractile objects with a wide range of spectral sensitivity. Its application is reported for investigating the oscillatory contraction activity of plasmodial strands of the slime mold physarum polycephalum. (authors). 15 refs., 7 figs.,

  13. Imaging the Microscopic Structure of Shear Thinning and Thickening Colloidal Suspensions

    KAUST Repository

    Cheng, X.

    2011-09-01

    The viscosity of colloidal suspensions varies with shear rate, an important effect encountered in many natural and industrial processes. Although this non-Newtonian behavior is believed to arise from the arrangement of suspended particles and their mutual interactions, microscopic particle dynamics are difficult to measure. By combining fast confocal microscopy with simultaneous force measurements, we systematically investigate a suspension\\'s structure as it transitions through regimes of different flow signatures. Our measurements of the microscopic single-particle dynamics show that shear thinning results from the decreased relative contribution of entropic forces and that shear thickening arises from particle clustering induced by hydrodynamic lubrication forces. This combination of techniques illustrates an approach that complements current methods for determining the microscopic origins of non-Newtonian flow behavior in complex fluids.

  14. A novel cryogenic scanning laser microscope tested on Josephson tunnel junctions

    DEFF Research Database (Denmark)

    Holm, Jesper; Mygind, Jesper

    1995-01-01

    A novel cryogenic scanning laser microscope with a spatial resolution of less than 5 µm has been designed for on-chip in situ investigations of the working properties of normal and superconducting circuits and devices. The instrument relies on the detection of the electrical response of the circuit...... to a very localized heating induced by irradiation with 675 nm wavelength light from a semiconductor laser. The hot spot is moved by a specially designed piezoelectric scanner sweeping the tip of a single-mode optical fiber a few µm above the circuit. Depending on the scanner design the scanning area can...... be as large as 50×500 µm2 at 4.2 K. The microscope can be operated in the temperature range 2–300 K using a standard temperature controller. The central microscope body is mounted inside the vacuum can of a dip-stick-type cryoprobe. A damped spring system is used to reduce interference from extraneous...

  15. [Study on microscopic identification of Astragalus complanatus and A. adsurgens seeds].

    Science.gov (United States)

    Li, Xiao-lin; Shao, Ai-juan; Zhan, Xiao-ri; Wei, Ying; Huang, Lu-qi

    2015-04-01

    Astragalus adsurgens seed is one of the most common adulterants of Astragali Complanati Semen in the market, whose morphological characteristics are very similar with A. complanatus seeds (Astragali Complanati Semen). Many identification methods have been reported, such as morphological identification, fluorescence method, ultraviolet spectrophotometry, TLC, HPLC, protein electrophoresis and so on, but there's no much about microscopic identification. In the present study, the morphological characteristics and microscopic characteristics of these two seeds were investigated, which could provide scientific evidence for the identification and classification of Astragali Complanati Semen. Our results showed that these two seeds were slightly different in the color and the appearance, but significantly different in the microstructure of the seed coat and the hilum, and the distribution of fat droplets in the cotyledon cells. So these microscopic characteristics can be applied for the identification of Astragali Complanati Semen.

  16. Comparing the photocatalytic activity of TiO2 at macro- and microscopic scales

    DEFF Research Database (Denmark)

    Torras-Rosell, Antoni; Johannsen, Sabrina Rostgaard; Dirscherl, Kai

    2016-01-01

    This study focuses on the characterization of photocatalytic TiO2 coatings using Kelvin probe force microscopy. While most photocatalytic experiments are carried out at a macroscopic scale, Kelvin probe force microscopy is a microscopic technique that is surface sensitive. In order to link...... microscale results to macroscopic experiments, a simple method to establish the relation between Kelvin probe force microscopy and electrochemical measurements is presented by the calibration of a reference sample consisting of epitaxial deposited Cu-Ni-Au that is used as a transfer standard....... The photocatalytic properties of TiO2 at macro- and microscopic scales are investigated by comparing photocatalytic degradation of acetone and electrochemical experiments to Kelvin probe force microscopy. The good agreement between the macro- and microscopic experiments suggests that Kelvin probe force microscopy...

  17. Comparing the photocatalytic activity of TiO2at macro- and microscopic scales.

    Science.gov (United States)

    Torras-Rosell, Antoni; Johannsen, Sabrina Rostgaard; Dirscherl, Kai; Daviðsdóttir, Svava; Jeppesen, Christian Sloth; Louring, Sascha; Andersen, Inge Hald

    2017-05-01

    This study focuses on the characterization of photocatalytic TiO 2 coatings using Kelvin probe force microscopy. While most photocatalytic experiments are carried out at a macroscopic scale, Kelvin probe force microscopy is a microscopic technique that is surface sensitive. In order to link microscale results to macroscopic experiments, a simple method to establish the relation between Kelvin probe force microscopy and electrochemical measurements is presented by the calibration of a reference sample consisting of epitaxial deposited Cu-Ni-Au that is used as a transfer standard. The photocatalytic properties of TiO 2 at macro- and microscopic scales are investigated by comparing photocatalytic degradation of acetone and electrochemical experiments to Kelvin probe force microscopy. The good agreement between the macro- and microscopic experiments suggests that Kelvin probe force microscopy can be a valuable tool towards the understanding, standardization and design of TiO 2 -based solutions in photocatalytic applications.

  18. Nonequilibrium Distribution of the Microscopic Thermal Current in Steady Thermal Transport Systems

    KAUST Repository

    Yukawa, Satoshi

    2010-01-01

    Nonequilibrium distribution of the microscopic thermal current is investigated by direct molecular dynamics simulations. The microscopic thermal current in this study is defined by a flow of kinetic energy carried by a single particle. Asymptotic parallel and antiparallel tails of the nonequilibrium distribution to an average thermal current are identical to ones of equilibrium distribution with different temperatures. These temperatures characterizing the tails are dependent on a characteristic length in which a memory of dynamics is completely erased by several particle collisions. This property of the tails of nonequilibrium distribution is confirmed in other thermal transport systems. In addition, statistical properties of a particle trapped by a harmonic potential in a steady thermal conducting state are also studied. This particle feels a finite force parallel to the average thermal current as a consequence of the skewness of the distribution of the current. This force is interpreted as the microscopic origin of thermophoresis.

  19. Microscopic local elements in the phosphating process

    Energy Technology Data Exchange (ETDEWEB)

    Zimmermann, D.; Munoz, A.G.; Schultze, J.W

    2003-09-30

    The addition of Ni{sup 2+} to the phosphating bath improves the corrosion stability as well as the adhesion of coating layers. This is caused by the formation of Ni deposits on the base of pores of the phosphate layer. They do not only catalyse the surface reactions but generate a more corrosion resistant surface as well. The deposition of Ni during the phosphating of electrogalvanised steel was studied in aqueous solutions by simultaneous measurement of the rest potential and electrode capacity in dependence on time, temperature and bath composition. The electrochemical response of the system was corroborated with SEM pictures, gravimetric measurements and X-ray fluorescence analysis. Rest potential patterns under different solution and initial surface conditions were interpreted by microscopic local elements. During the deposition of the phosphate layer, the cementation of Ni on the initially corroding Zn gives rise to the formation of surface Ni-Zn alloys, providing cathodic centres where the reduction of H{sup +} and accelerators (NO{sub 2}{sup -}, NO{sub 3}{sup -}) is favoured. The process matches with a quasi-instantaneous displacement of the rest potential from that corresponding to the Zn/Zn{sup 2+} couple towards the corrosion potentials of cementated Ni-rich alloys. The appearance of a simultaneous characteristic capacity peak was analysed in terms of the surface changes due to Ni-cementation together with an increment of the growth rate of phosphate crystals and the formation of oxide films. Microscopic local Ni deposits have an extension of some micrometer and a thickness of few hundred nanometer up to 1 {mu}m.

  20. Ergonomic Microscope: Need of the Hour

    Science.gov (United States)

    Mhaske, Shubhangi Ashok; Ahmad, Malik Ajaz; Yuwanati, Monal B.; Prabhu, Shweta; Pardhe, Nilesh

    2015-01-01

    Background Prolonged use of conventional microscope develops musculo-skeletal injuries like chronic pain syndrome, including shoulder, neck, back aches & fatigue. Since the problems go unnoticed, the injuries can lead to some serious permanent damages. This further leads to a compromise in the health and welfare of the person and the institute. Hence, an understanding about the ergonomics is the need of the hour in this postmodern era. Inspite of few studies and surveys about ergonomics, there is still a steep rise in the musculoskeletal disorders. Aim of the Study The aim of our study was to gauge the general awareness of pathologists, microbiologists and oral pathologists towards ergonomics in their profession. Materials and Methods A cross-sectional survey based study was de­signed, which included a questionnaire. The questionnaire included multiple choice questions with four alternatives. Professionals (pathologists, microbiologists and oral pathologists) were included in the survey. Teaching faculty (Professors, Associate Professors and Lecturers) and Post graduate students formed the study group. Results and Observations The response to the questionnaire was 100%. Less than 50% of oral pathologists were aware of the importance of ergonomics in their profession. The most common site affected was neck and back. One of the drastic observations was that, Oral Pathologists suffered from a combination of problems affecting neck, back, eyes, headache, shoulders, arms and wrists. Conclusion Increase in our understanding regarding ergonomic­ally designed microscopes can increase our efficiency and in turn improve our general well-being. With improvements in ergonomics, professionals would be able to modify and optimize their working conditions. Certain guidelines need to be followed by the profes­sionals to reduce chances of musculoskeletal disorders. PMID:26155565

  1. Fission dynamics with microscopic level densities

    Science.gov (United States)

    Randrup, Jørgen; Ward, Daniel; Carlsson, Gillis; Døssing, Thomas; Möller, Peter; Åberg, Sven

    2018-03-01

    Working within the Langevin framework of nuclear shape dynamics, we study the dependence of the evolution on the degree of excitation. As the excitation energy of the fissioning system is increased, the pairing correlations and the shell effects diminish and the effective potential-energy surface becomes ever more liquid-drop like. This feature can be included in the treatment in a formally well-founded manner by using the local level densities as a basis for the shape evolution. This is particularly easy to understand and implement in the Metropolis treatment where the evolution is simulated by means of a random walk on the five-dimensional lattice of shapes for which the potential energy has been tabulated. Because the individual steps between two neighboring lattice sites are decided on the basis of the ratio of the statistical weights, what is needed is the ratio of the local level densities for those shapes, evaluated at the associated local excitation energies. For this purpose, we adapt a recently developed combinatorial method for calculating level densities which employs the same single-particle levels as those that were used for the calculation of the pairing and shell contributions to the macroscopic-microscopic deformation-energy surface. For each nucleus under consideration, the level density (for a fixed total angular momentum) is calculated microscopically for each of the over five million shapes given in the three-quadratic-surface parametrization. This novel treatment, which introduces no new parameters, is illustrated for the fission fragment mass distributions for selected uranium and plutonium cases.

  2. Metrological large range scanning probe microscope

    International Nuclear Information System (INIS)

    Dai Gaoliang; Pohlenz, Frank; Danzebrink, Hans-Ulrich; Xu Min; Hasche, Klaus; Wilkening, Guenter

    2004-01-01

    We describe a metrological large range scanning probe microscope (LR-SPM) with an Abbe error free design and direct interferometric position measurement capability, aimed at versatile traceable topographic measurements that require nanometer accuracy. A dual-stage positioning system was designed to achieve both a large measurement range and a high measurement speed. This dual-stage system consists of a commercially available stage, referred to as nanomeasuring machine (NMM), with a motion range of 25 mmx25 mmx5 mm along x, y, and z axes, and a compact z-axis piezoelectric positioning stage (compact z stage) with an extension range of 2 μm. The metrological LR-SPM described here senses the surface using a stationary fixed scanning force microscope (SFM) head working in contact mode. During operation, lateral scanning of the sample is performed solely by the NMM. Whereas the z motion, controlled by the SFM signal, is carried out by a combination of the NMM and the compact z stage. In this case the compact z stage, with its high mechanical resonance frequency (greater than 20 kHz), is responsible for the rapid motion while the NMM simultaneously makes slower movements over a larger motion range. To reduce the Abbe offset to a minimum the SFM tip is located at the intersection of three interferometer measurement beams orientated in x, y, and z directions. To improve real time performance two high-end digital signal processing (DSP) systems are used for NMM positioning and SFM servocontrol. Comprehensive DSP firmware and Windows XP-based software are implemented, providing a flexible and user-friendly interface. The instrument is able to perform large area imaging or profile scanning directly without stitching small scanned images. Several measurements on different samples such as flatness standards, nanostep height standards, roughness standards as well as sharp nanoedge samples and 1D gratings demonstrate the outstanding metrological capabilities of the instrument

  3. Direct microscopic image and measurement of the atomization process of a port fuel injector

    Science.gov (United States)

    Esmail, Mohamed; Kawahara, Nobuyuki; Tomita, Eiji; Sumida, Mamoru

    2010-07-01

    The main objective of this study is to observe and investigate the phenomena of atomization, i.e. the fuel break-up process very close to the nozzle exit of a practical port fuel injector (PFI). In order to achieve this objective, direct microscopic images of the atomization process were obtained using an ultra-high-speed video camera that could record 102 frames at rates of up to 1 Mfps, coupled with a long-distance microscope and Barlow lens. The experiments were carried out using a PFI in a closed chamber at atmospheric pressure. Time-series images of the spray behaviour were obtained with a high temporal resolution using backlighting. The direct microscopic images of a liquid column break-up were compared with experimental results from laser-induced exciplex fluorescence (LIEF), and the wavelength obtained from the experimental results compared with that predicated from the Kelvin-Helmholtz break-up model. The droplet size diameters from a ligament break-up were compared with results predicated from Weber's analysis. Furthermore, experimental results of the mean droplet diameter from a direct microscopic image were compared with the results obtained from phase Doppler anemometry (PDA) experimental results. Three conclusions were obtained from this study. The atomization processes and detailed characterizations of the break-up of a liquid column were identified; the direct microscopic image results were in good agreement with the results obtained from LIEF, experimental results of the wavelength were in good agreement with those from the Kelvin-Helmholtz break-up model. The break-up process of liquid ligaments into droplets was investigated, and Weber's analysis of the predicated droplet diameter from ligament break-up was found to be applicable only at larger wavelengths. Finally, the direct microscopic image method and PDA method give qualitatively similar trends for droplet size distribution and quantitatively similar values of Sauter mean diameter.

  4. Implementation of a virtual correlative light and transmission electron microscope.

    Science.gov (United States)

    Voigt, Tilman; Zuber, Benoît; Gawatz, Gerlinde; Herrmann, Gudrun

    2013-07-01

    In the long run, the widespread use of slide scanners by pathologists requires an adaptation of teaching methods in histology and cytology in order to target these new possibilities of image processing and presentation via the internet. Accordingly, we were looking for a tool with the possibility to teach microscopic anatomy, histology, and cytology of tissue samples which would be able to combine image data from light and electron microscopes independently of microscope suppliers. With the example of a section through the villus of jejunum, we describe here how to process image data from light and electron microscopes in order to get one image-stack which allows a correlation of structures from the microscopic anatomic to the cytological level. With commercially available image-presentation software that we adapted to our needs, we present here a platform which allows for the presentation of this new but also of older material independently of microscope suppliers. Copyright © 2013 Wiley Periodicals, Inc.

  5. The long road to the use of microscope in clinical medicine in vivo: from early pioneering proposals to the modern perspectives of optical biopsy.

    Science.gov (United States)

    Ponti, Giovanni; Muscatello, Umberto; Sgantzos, Markos

    2015-01-01

    For a long period the scientists did not recognized the potentialities of the compound microscope in medicine. Only few scientists recognized the potentialities of the microscope for the medicine; among them G. Campani who proposed the utilization of his microscope to investigate the skin lesions directly on the patient. The proposal was illustrated in a letter Acta Eruditorum of 1686. The recent development of optical techniques, capable of providing in-focus images of an object from different planes with high spatial resolution, significantly increased the diagnostic potential of the microscope directly on the patient.

  6. A compact scanning soft X-ray microscope

    International Nuclear Information System (INIS)

    Trail, J.A.

    1989-01-01

    Soft x-ray microscopes operating at wavelengths between 2.3 nm and 4.4 nm are capable of imaging wet biological cells with a resolution many times that of a visible light microscope. Several such soft x-ray microscopes have been constructed. However, with the exception of contact microscopes, all use synchrotrons as the source of soft x-ray radiation and Fresnel zone plates as the focusing optics. These synchrotron based microscopes are very successful but have the disadvantage of limited access. This dissertation reviews the construction and performance of a compact scanning soft x-ray microscope whose size and accessibility is comparable to that of an electron microscope. The microscope uses a high-brightness laser-produced plasma as the soft x-ray source and normal incidence multilayer-coated mirrors in a Schwarzschild configuration as the focusing optics. The microscope operates at a wavelength of 14 nm, has a spatial resolution of 0.5 μm, and has a soft x-ray photon flux through the focus of 10 4 -10 5 s -1 when operated with only 170 mW of average laser power. The complete system, including the laser, fits on a single 4' x 8' optical table. The significant components of the compact microscope are the laser-produced plasma (LPP) source, the multilayer coatings, and the Schwarzschild objective. These components are reviewed, both with regard to their particular use in the current microscope and with regard to extending the microscope performance to higher resolution, higher speed, and operation at shorter wavelengths. Measurements of soft x-ray emission and debris emission from our present LPP source are presented and considerations given for an optimal LPP source. The LPP source was also used as a broadband soft x-ray source for measurement of normal incidence multilayer mirror reflectance in the 10-25 nm spectral region

  7. Microscopic cross-section measurements by thermal neutron activation

    International Nuclear Information System (INIS)

    Avila L, J.

    1987-08-01

    Microscopic cross sections measured by thermal neutron activation using RP-0 reactor at the Peruvian Nuclear Energy Institute. The method consists in measuring microscopic cross section ratios through activated samples, requiring being corrected in thermal and epithermal energetic range by Westcott formalism. Furthermore, the comptage ratios measured for each photopeak to its decay fraction should be normalized from interrelation between both processes above, activation microscopic cross sections are obtained

  8. Evaluation of a completely robotized neurosurgical operating microscope.

    Science.gov (United States)

    Kantelhardt, Sven R; Finke, Markus; Schweikard, Achim; Giese, Alf

    2013-01-01

    Operating microscopes are essential for most neurosurgical procedures. Modern robot-assisted controls offer new possibilities, combining the advantages of conventional and automated systems. We evaluated the prototype of a completely robotized operating microscope with an integrated optical coherence tomography module. A standard operating microscope was fitted with motors and control instruments, with the manual control mode and balance preserved. In the robot mode, the microscope was steered by a remote control that could be fixed to a surgical instrument. External encoders and accelerometers tracked microscope movements. The microscope was additionally fitted with an optical coherence tomography-scanning module. The robotized microscope was tested on model systems. It could be freely positioned, without forcing the surgeon to take the hands from the instruments or avert the eyes from the oculars. Positioning error was about 1 mm, and vibration faded in 1 second. Tracking of microscope movements, combined with an autofocus function, allowed determination of the focus position within the 3-dimensional space. This constituted a second loop of navigation independent from conventional infrared reflector-based techniques. In the robot mode, automated optical coherence tomography scanning of large surface areas was feasible. The prototype of a robotized optical coherence tomography-integrated operating microscope combines the advantages of a conventional manually controlled operating microscope with a remote-controlled positioning aid and a self-navigating microscope system that performs automated positioning tasks such as surface scans. This demonstrates that, in the future, operating microscopes may be used to acquire intraoperative spatial data, volume changes, and structural data of brain or brain tumor tissue.

  9. Focal Molography: Coherent Microscopic Detection of Biomolecular Interaction

    Directory of Open Access Journals (Sweden)

    Christof Fattinger

    2014-08-01

    Full Text Available We introduce and theoretically investigate here a novel analytical method that we have called focal molography, in which molecular interactions are made visible through scattering of coherent light by a coherent pattern of molecules. The scattered light quantifies the presence of molecules at molecular interaction sites. It is separated from noncoherent background scatter by a combination of local dark-field illumination, interference enhancement, and spatial filtering. The latter is achieved by holographic focusing of the wave field generated by the coherently assembled molecules onto an Airy disk and by subtraction of the noncoherent irradiance in the focal plane outside the disk from the irradiance in the disk. This new microscopic method allows distinct detection of low-refractive-index contrast in the nanoenvironment of biomolecules from which information on the interaction of the coherently assembled molecules with molecules in a liquid or gaseous sample may be deduced. The noncoherent surroundings of the coherently assembled molecules consist of freely diffusing solvent and solute molecules. The surroundings, as well as changes in temperature, do not contribute to the coherent signal in the diffraction focus. Interference lithography or high-resolution-imaging lithography can be used to synthesize the coherent pattern of molecules on a monolithic substrate. The coherent pattern of molecules constitutes a synthetic phase hologram that creates a diffraction-limited light wave. We suggest the term “mologram” for the coherent assembly of functional nanostructures and the term “focal molography” for label-free or labeled analysis of molecular interactions through the measurement of the properties of light in the focus of the mologram. We derive analytical formulas that express the detection signal and the sensitivity of focal molography on the surface of a high-refractive-index thin-film optical waveguide in terms of known parameters

  10. A versatile atomic force microscope integrated with a scanning electron microscope.

    Science.gov (United States)

    Kreith, J; Strunz, T; Fantner, E J; Fantner, G E; Cordill, M J

    2017-05-01

    A versatile atomic force microscope (AFM), which can be installed in a scanning electron microscope (SEM), is introduced. The flexible design of the instrument enables correlated analysis for different experimental configurations, such as AFM imaging directly after nanoindentation in vacuum. In order to demonstrate the capabilities of the specially designed AFM installed inside a SEM, slip steps emanating around nanoindents in single crystalline brass were examined. This example showcases how the combination of AFM and SEM imaging can be utilized for quantitative dislocation analysis through the measurement of the slip step heights without the hindrance of oxide formation. Finally, an in situ nanoindentation technique is introduced, illustrating the use of AFM imaging during indentation experiments to examine plastic deformation occurring under the indenter tip. The mechanical indentation data are correlated to the SEM and AFM images to estimate the number of dislocations emitted to the surface.

  11. Lateral force microscope calibration using a modified atomic force microscope cantilever

    International Nuclear Information System (INIS)

    Reitsma, M. G.

    2007-01-01

    A proof-of-concept study is presented for a prototype atomic force microscope (AFM) cantilever and associated calibration procedure that provide a path for quantitative friction measurement using a lateral force microscope (LFM). The calibration procedure is based on the method proposed by Feiler et al. [Rev. Sci. Instrum. 71, 2746 (2000)] but allows for calibration and friction measurements to be carried out in situ and with greater precision. The modified AFM cantilever is equipped with lateral lever arms that facilitate the application of normal and lateral forces, comparable to those acting in a typical LFM friction experiment. The technique allows the user to select acceptable precision via a potentially unlimited number of calibration measurements across the full working range of the LFM photodetector. A microfabricated version of the cantilever would be compatible with typical commercial AFM instrumentation and allow for common AFM techniques such as topography imaging and other surface force measurements to be performed

  12. Phase-shifting interference microscope with extendable field of measurement

    Science.gov (United States)

    Lin, Shyh-Tsong; Hsu, Wei-Feng; Wang, Ming-Shiang

    2018-04-01

    An innovative phase-shifting interference microscope aimed at extending the field of measurement is proposed in this paper. The microscope comprises a light source module, a phase modulation module, and an interferometric module, which reconstructs the micro-structure contours of samples using the five-step phase-shifting algorithm. This paper discusses the measurement theory and outlines the configuration, experimental setup, and experimental results obtained using the proposed interference microscope. The results confirm the efficacy of the microscope, achieving a standard deviation of 2.4 nm from a step height of 86.2 nm in multiple examinations.

  13. van Leeuwenhoek microscopes-where are they now?

    Science.gov (United States)

    Robertson, Lesley A

    2015-05-01

    When Antonie van Leeuwenhoek died, he left over 500 simple microscopes, aalkijkers (an adaption of his microscope to allow the examination of blood circulation in the tails of small eels) and lenses, yet now there are only 10 microscopes with a claim to being authentic, one possible aalkijker and six lenses. He made microscopes with more than one lens, and possibly three forms of the aalkijker. This paper attempts to establish exactly what he left and trace the fate of some of the others using the earliest possible documents and publications. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. Generalized Dependence of Semi-Microscopic Folding-Model Parameters for Alpha-Particles in the Field of Low and Medium Energy

    CERN Document Server

    Kuterbekov, K A; Penionzhkevich, Yu E; Zholdybaev, T K

    2003-01-01

    Energy and mass dependences of the semi-microscopic alpha-particle potential parameters have been investigated for the first time. In general, a good description of elastic and inelastic differential and total reaction cross sections for different nuclei using the revealed global parameters has been obtained within the framework of semi-microscopic approaches.

  15. Using a university characterization facility to educate the public about microscopes: light microscopes to SEM

    Science.gov (United States)

    Healy, Nancy; Henderson, Walter

    2015-10-01

    The National Nanotechnology Infrastructure Network (NNIN)1is an integrated partnership of 14 universities across the US funded by NSF to support nanoscale researchers. The NNIN education office is located at the Institute of Electronics and Nanotechnology at the Georgia Institute of Technology. At Georgia Tech we offer programs that integrate the facility and its resources to educate the public about nanotechnology. One event that has proved highly successful involves using microscopes in our characterization suite to educate a diverse audience about a variety of imaging instruments. As part of the annual Atlanta Science Festival (ATLSF)2 we provided an event entitled: "What's all the Buzz about Nanotechnology?" which was open to the public and advertised through a variety of methods by the ATLSF. During the event, we provided hands-on demos, cleanroom tours, and activities with three of our microscopes in our recently opened Imaging and Characterization Facility: 1. Keyence VHX-600 Digital Microscope; 2. Hitachi SU823 FE-SEM; and 3. Hitachi TM 3000. During the two hour event we had approximately 150 visitors including many families with school-aged children. Visitors were invited to bring a sample for scanning with the TM-3000. This paper will discuss how to do such an event, lessons learned, and visitor survey results.

  16. Low-power noncontact photoacoustic microscope for bioimaging applications

    Science.gov (United States)

    Sathiyamoorthy, Krishnan; Strohm, Eric M.; Kolios, Michael C.

    2017-04-01

    An inexpensive noncontact photoacoustic (PA) imaging system using a low-power continuous wave laser and a kilohertz-range microphone has been developed. The system operates in both optical and PA imaging modes and is designed to be compatible with conventional optical microscopes. Aqueous coupling fluids are not required for the detection of the PA signals; air is used as the coupling medium. The main component of the PA system is a custom designed PA imaging sensor that consists of an air-filled sample chamber and a resonator chamber that isolates a standard kilohertz frequency microphone from the input laser. A sample to be examined is placed on the glass substrate inside the chamber. A laser focused to a small spot by a 40× objective onto the substrate enables generation of PA signals from the sample. Raster scanning the laser over the sample with micrometer-sized steps enables high-resolution PA images to be generated. A lateral resolution of 1.37 μm was achieved in this proof of concept study, which can be further improved using a higher numerical aperture objective. The application of the system was investigated on a red blood cell, with a noise-equivalent detection sensitivity of 43,887 hemoglobin molecules (72.88×10-21 mol or 72.88 zeptomol). The minimum pressure detectable limit of the system was 19.1 μPa. This inexpensive, compact noncontact PA sensor is easily integrated with existing commercial optical microscopes, enabling optical and PA imaging of the same sample. Applications include forensic measurements, blood coagulation tests, and monitoring the penetration of drugs into human membrane.

  17. Histological evaluation of thyroid lesions using a scanning acoustic microscope

    Directory of Open Access Journals (Sweden)

    Miura K

    2014-02-01

    Full Text Available Katsutoshi Miura,1 Hiroyuki Mineta2 1Department of Health Science, Pathology, and Anatomy, 2Department of Otorhinolaryngology, Hamamatsu University School of Medicine, Hamamatsu, Japan Purpose: A scanning acoustic microscope (SAM uses an ultrasound to image an object by plotting the speed-of-sound (SOS through tissues on screen. Because hard tissues result in great SOS, SAM can provide data on the tissue elasticity. This paper investigated the utility of SAM in evaluating thyroid lesions. Methods: Formalin-fixed, paraffin sections were scanned with a 120 MHz transducer. SOS through each area was calculated and plotted on the screen to provide histological images, and SOS of each lesion was compared and statistically analyzed. Results: High-concentrated colloids, red blood cells, and collagen fibers showed great SOS, while low-concentrated colloids, parathyroids, lymph follicles, and epithelial tissues including carcinomas demonstrated lower SOS. SAM clearly discriminated structure of thyroid components corresponding to low magnification of light microscopy. Thyroid tumors were classified into three groups by average SOS: the fast group consisted of follicular adenomas/carcinomas and malignant lymphomas; the slow group contained poorly differentiated/undifferentiated carcinomas; and the intermediate group comprised papillary/medullary carcinomas. Fragmented colloids, irregular-shaped follicles, and desmoplastic reactions were observed in the invasive area of surrounding carcinomas. Conclusion: The SAM imaging method had the following benefits: 1 precise images were acquired in a few minutes without special staining; 2 structural irregularity and desmoplastic reactions, which indicated malignancy, were detected; 3 images reflected tissue elasticity, which was statistically comparable among lesions by SOS; 4 follicular functional activity was predictable by converting colloid concentration to SOS; and 5 tumor classification was predictable by SOS

  18. AN ANTHOLOGY OF THE DISTINGUISHED ACHIEVEMENTS IN A SCIENCE AND TECHNIQUE. PART 23: INVENTION OF MICROSCOPE AND STUDY OF MICROSCOPIC WORLD

    Directory of Open Access Journals (Sweden)

    M.I. Baranov

    2014-12-01

    Full Text Available A short essay is resulted from world history of invention of microscopes. The basic types of microscopes are described; directions and some results of their application are indicated at the study of microscopic world.

  19. AN ANTHOLOGY OF THE DISTINGUISHED ACHIEVEMENTS IN A SCIENCE AND TECHNIQUE. PART 23: INVENTION OF MICROSCOPE AND STUDY OF MICROSCOPIC WORLD

    OpenAIRE

    M.I. Baranov

    2014-01-01

    A short essay is resulted from world history of invention of microscopes. The basic types of microscopes are described; directions and some results of their application are indicated at the study of microscopic world.

  20. Novel Multiwavelength Microscopic Scanner for Mouse Imaging

    Directory of Open Access Journals (Sweden)

    Herlen Alencar

    2005-11-01

    Full Text Available Real-time in vivo imaging of molecular targets at (subcellular resolution is essential in better understanding complex biology. Confocal microscopy and multiphoton microscopy have been used in the past to achieve this goal, but their true capabilities have often been limited by bulky optics and difficult experimental set-ups requiring exteriorized organs. We describe here the development and validation of a unique nearinfrared laser scanning microscope system that uses novel optics with a millimeter footprint. Optimized for use in the far red and near-infrared ranges, the system allows an imaging depth that extends up to 500 Mm from a 1.3-mm-diameter stick objective, which is up to 2 cm in length. We show exceptionally high spatial, temporal, and multiwavelength resolutions of the system and show that it can be applied to virtually any internal organ through a keyhole surgical access. We demonstrate that, when combined with novel far red imaging probes, it is possible to image the cellular details of many organs and disease processes. The new optics, coupled with the use of near-infrared probes, should prove immensely valuable for in vivo cancer imaging.

  1. Microscopic activity patterns in the naming game

    International Nuclear Information System (INIS)

    Dall'Asta, Luca; Baronchelli, Andrea

    2006-01-01

    The models of statistical physics used to study collective phenomena in some interdisciplinary contexts, such as social dynamics and opinion spreading, do not consider the effects of the memory on individual decision processes. In contrast, in the naming game, a recently proposed model of language formation, each agent chooses a particular state, or opinion, by means of a memory-based negotiation process, during which a variable number of states is collected and kept in memory. In this perspective, the statistical features of the number of states collected by the agents become a relevant quantity to understand the dynamics of the model, and the influence of topological properties on memory-based models. By means of a master equation approach, we analyse the internal agent dynamics of the naming game in populations embedded on networks, finding that it strongly depends on very general topological properties of the system (e.g. average and fluctuations of the degree). However, the influence of topological properties on the microscopic individual dynamics is a general phenomenon that should characterize all those social interactions that can be modelled by memory-based negotiation processes

  2. Thermal Variations of Operative Microscopes in Otology.

    Science.gov (United States)

    Imbery, T Edward; Tampio, Alex J; Nicholas, Brian D

    2017-07-01

    Objectives (1) Measure temperature variations achieved by common otomicroscopes. (2) Raise awareness about possible thermal injury during otologic procedures with the advent of newer, high-powered otomicroscopes. (3) Describe optical technology that aims to reduce the potential for thermal injury. Methods A variety of otomicroscopes, with different light sources (ranging from 100W halogen to 300W xenon), were studied. Temperatures were recorded from human auricular skin with a noncontact infrared thermometer at various microscope light intensities and with use of irrigation. Multiple recordings were done at 5-minute intervals, and a working distance of 225 mm was maintained. Results Maximum skin temperatures were found to plateau relatively quickly, with higher-wattage xenon light sources reaching greater temperatures. One-way analysis of variance revealed significant differences in temperatures with decreased light intensities. High-wattage xenon light sources reached significantly higher temperatures when compared with halogen models. Discussion There is substantial variation in maximal skin temperatures reached by otomicroscopes. Temperatures can be decreased to safe levels by reducing light intensity and with use of irrigation. The maximum temperature obtained in our study was 41.4°C. Second-degree skin burns have been described with prolonged exposures to temperatures >44°C. Implications for Practice Given the described potential for burns, surgeons performing procedures on the ear and temporal bone should take precautions to diminish temperature in the operative field.

  3. Visible and occult microscopic lesions of endometriosis

    Directory of Open Access Journals (Sweden)

    Khaleque Newaz Khan

    2014-11-01

    Full Text Available Endometriosis is a multifactorial disease mostly affecting women of reproductive age and is associated with chronic pelvic pain and infertility. Even after 300 years, most of the literature claims that pathogenesis and/or pathophysiology of endometriosis is still elusive. Recurrence of pain and lesion continues to occur after effective medical or surgical therapies. Once generated within the pelvis due to retrograde entry of menstrual debris, peritoneal endometriotic lesions time-dependently change their color appearance resulting from certain biochemical change within lesions. A variable pattern of endometriotic lesions within the pelvis can be detected by laparoscopy as visible peritoneal endometriosis. It is generally believed that besides ovarian steroid hormones, the growth of endometriosis can be regulated by the innate immune system in the pelvic microenvironment by their interaction with endometrial cells and immune cells. Even with the careful eyes of an expert surgeon, we may sometimes miss detecting peritoneal lesion within the peritoneal cavity or deep into the peritoneum. In such a case, random collection of normal peritoneum may carry the possibility to identify some hidden endometriotic lesions by microscopy and these lesions can be named as occult (invisible microscopic endometriosis (OME. Here, we discuss the color appearance of peritoneal lesions and activity of these lesions by analysis of a panel of activity markers. Finally we discuss our recent findings on OME, their biological and clinical significance, and try to make a possible link in the origin between visible endometriosis and OME.

  4. Soft x-ray spectro microscope

    International Nuclear Information System (INIS)

    Campuzano, J.C.; Jennings, G.; Beaulaigue, L.; Rodricks, B.G.; Brizard, C.

    1990-01-01

    This paper reports on the development of an x-ray photoelectron microscope that provides spatial as well as chemical information on the nature of the sample. Photons from the Aladdin Synchrotron at the Synchrotron Radiation Center in Stoughton, WI are monochromatized by an extended-range Grasshopper monochromator covering the range 40 to 1500 eV with energy resolution varying between 10 and 200 MeV. The monochromatized radiation generates photoelectrons in the sample, which are energy-analyzed with a resolving power E|ΔE > 5 x 10 4 and imaged by a multichannel plate array. The visible image is transferred to a computer by a virtual-phase charge-coupled device camera with a dynamic range of 4096:1. Preliminary coarse measurements indicate a spatial resolution of the instrument of better than 1μm, although a limit of 600 Angstrom is possible. The instrument provides chemical shift-resolved images of low-lying core levels in a variety of samples

  5. Mechanism of diarrhea in microscopic colitis.

    Science.gov (United States)

    Protic, Marijana; Jojic, Njegica; Bojic, Daniela; Milutinovic, Svetlana; Necic, Dusanka; Bojic, Bozidar; Svorcan, Petar; Krstic, Miodrag; Popovic, Obren

    2005-09-21

    To search the pathophysiological mechanism of diarrhea based on daily stool weights, fecal electrolytes, osmotic gap and pH. Seventy-six patients were included: 51 with microscopic colitis (MC) (40 with lymphocytic colitis (LC); 11 with collagenous colitis (CC)); 7 with MC without diarrhea and 18 as a control group (CG). They collected stool for 3 d. Sodium and potassium concentration were determined by flame photometry and chloride concentration by titration method of Schales. Fecal osmotic gap was calculated from the difference of osmolarity of fecal fluid and double sum of sodium and potassium concentration. Fecal fluid sodium concentration was significantly increased in LC 58.11+/-5.38 mmol/L (Pdiarrhea compared to fecal osmotic gap. Seven (13.3%) patients had osmotic diarrhea. Diarrhea in MC mostly belongs to the secretory type. The major pathophysiological mechanism in LC could be explained by a decrease of active sodium absorption. In CC, decreased Cl/HCO3 exchange rate and increased chloride secretion are coexistent pathways.

  6. A microscopic approach to amplitude modulation with small signal of current

    International Nuclear Information System (INIS)

    Chiaretti, G.; Brambilla, M.; Milani, M.

    1988-01-01

    A microscopic approach to semiconductor injection laser dynamics is discussed to investigate the amplitude modulation with a small current signal in semiconductor lasers. An expression for the resonance frequency ν r is obtained as a function of microscopic parameters which characterize the laser system. This expression can be compared with the one derived from a standard rate equations approach, showing the existence of an additional factor. This factor leads to the prediction of a larger resonance frequency and consequently to a better agreement with the experimental data. The authors investigate the problem of amplitude modulation with small current signal in semiconductor lasers deriving an expression for the resonance frequency as a function of microscopic parameters which characterize the laser system and as a function of the injected current. This approach is based on the analysis of the competition among the fundamental microscopic processes typical of light-matter interaction and of the loss and pumping mechanisms that are at work in a laser system

  7. Microscopic intraosseous extension of osteosarcoma: assessment on dynamic contrast-enhanced MRI

    International Nuclear Information System (INIS)

    Iwasawa, Tae; Tanaka, Yukichi; Aida, Noriko; Okuzumi, Shigeharu; Nishihira, Hirokazu; Nishimura, Gen

    1997-01-01

    Objective. This study investigated whether dynamic MRI could determine microscopic intraosseous invasion in osteosarcoma. Patients. Six patients with osteosarcoma who underwent total resection of the tumor after chemotherapy were studied. Design. The steepest slope value of the time-intensity curve was calculated on the basis of the first-pass method on dynamic MRI performed after chemotherapy. Slope value modified log=[100.(SI b -SI a )/(T b -T a )/SI a [, where SI a and SI b represent the signal intensity at time points T a and T b when the steepest slope started and ended, respectively. The slope value was correlated with the histological findings of the surgical specimens. The findings on conventional MRI were also reviewed. Results and conclusions. In five of six patients microscopic tumor invasion ranging from 1 to 3.5 cm in depth was pathologically proven. The slope value within the microscopic invasion (-0.052 ±0.267) was significantly greater than that of tumour-free marrow (-0.609 ±0.220) and less than that in areas showing macroscopic tumor invasion (0.595 ±0.483) (P <0.001). Histological examination disclosed the dilatation of small vessels within the macroscopic and microscopic invasion. Findings on conventional MRI varied among patients; microscopic invasion was not detected in one, underestimated in two, and overestimated in two. It is concluded that calculation of the slope value on dynamic MRI can discriminate regions of microscopic invasion from tumor-free marrow in patients with osteosarcoma after chemotherapy. (orig.). With 8 figs., 3 tabs

  8. Application of a new MR Microscope using an Independent Console System (MRMICS) for biological tissues in vitro

    International Nuclear Information System (INIS)

    Yoshioka, Hiroshi; Anno, Izumi; Itai, Yuji; Haishi, Tomoyuki; Adachi, Naotaka; Kose, Katsumi

    1999-01-01

    We studied microscopic MR images of the normal appendix in vitro using a new MR microscope system: MR Microscope using an Independent Console System (MRMICS). The MRMICS was placed in the clinical MR room, and the probe box was fixed on the bed of the 1.5 T clinical MR machine. T1-, T2-, and proton density-weighted images were obtained using spin echo sequences with an in-plane pixel size of 100 x 100 μm. Zonal structures of the appendix were clearly demonstrated with different contrast by different sequences. Therefore, the MRMICS is a useful add-on system for investigating microscopic MR images of biological tissues in vitro. (author)

  9. Soft X-ray microscope constructed with 130-nm spatial resolution using a high harmonic X-ray source

    International Nuclear Information System (INIS)

    Kim, Deuk Su; Park, Jong Ju; Lee, Kyoung Hwan; Park, Juyun; Nam, Chang Hee

    2009-01-01

    Using high harmonic radiation as an X-ray light source, a soft X-ray microscope with nanometer-scale spatial resolution was investigated. A transmission soft X-ray microscope was constructed using a Mo/Si multilayer concave mirror as a condenser and a Fresnel zone plate as a microscope objective. The high-order harmonic source at 13 nm, emitted from neon atoms driven by intense femtosecond laser pulses, was optimized by controlling laser chirp. Objects, patterned on 160-nm-thick hydrogen silsesquioxane coated on a 100-nm-thick Si 3 N 4 membrane, were used for imaging. The analysis of object images, captured on an X-ray charge-coupled device, showed that the spatial resolution of the microscope was about 130 nm, verifying the usefulness of the tabletop soft X-ray source. (author)

  10. Microscopic morphology of nitrogen fixing paranodules on wheat roots

    African Journals Online (AJOL)

    The size of paranodules did not increase during subsequent plant growth. Light microscopic examination and scanning electron microscope showed a large number of bacteria within the mucigel. In ultra thin sections of the nodule, bacterial cells were found in the intercellular space of the paranodules. In the latter case, ...

  11. Microscopic oxygen imaging based on fluorescein bleaching efficiency measurements

    DEFF Research Database (Denmark)

    Beutler, Martin; Heisterkamp, Ines M.; Piltz, Bastian

    2014-01-01

    by a charge-coupled-device (ccd) camera mounted on a fluorescence microscope allowed a pixelwise estimation of the ratio function in a microscopic image. Use of a microsensor and oxygen-consuming bacteria in a sample chamber enabled the calibration of the system for quantification of absolute oxygen...

  12. COMPARATIVE-STUDY OF 3 SEMIAUTOMATED SPECULAR MICROSCOPES

    NARCIS (Netherlands)

    LANDESZ, M; SIERTSEMA, JV; VANRIJ, G

    We compared two clinical video-assisted specular microscopes (Zeiss, noncontact, and the wide-field Keeler Konan sp 3300, contact) with an autofocus microscope (Konan noncon Robo-ca sp 8000, noncontact) with built-in analyzing software by studying the morphometry of the central corneal endothelium

  13. Catalysts under Controlled Atmospheres in the Transmission Electron Microscope

    DEFF Research Database (Denmark)

    Hansen, Thomas Willum; Wagner, Jakob Birkedal

    2014-01-01

    microscope, and since its invention by Ernst Ruska, the idea of imaging samples under gaseous atmospheres was envisioned. However, microscopes have traditionally been operated in high vacuum due to sensitive electron sources, sample contamination, and electron scattering off gas molecules resulting in loss...

  14. Measurement of the Resolution of the Optical Microscope.

    Science.gov (United States)

    Bowlt, C.

    1983-01-01

    Outlines procedures demonstrating that the aperture of a microscope objective limits resolving power and then, by using ancillary measurements made with a calibrated graticule in the microscope eyepiece, that the experimentally determined value for the maximum resolving power of a given objective is close to the value predicted by theory. (JN)

  15. Development of a DMD-based fluorescence microscope

    NARCIS (Netherlands)

    Chakrova, N.; Rieger, B.; Stallinga, S.

    2015-01-01

    We present a versatile fluorescence microscope, built by complementing a conventional fluorescence microscope with a digital micro-mirror device (DMD) in the illumination path. Arbitrary patterns can be created on the DMD and projected onto the sample. This patterned illumination can be used to

  16. Students' Conceptions about the Sub-Microscopic Approach to ...

    African Journals Online (AJOL)

    NICO

    microscopic particles (molecules, atoms, ions, electrons, protons, neutrons) present in the system being studied. This approach, the sub-microscopic approach to explanations, is very widely applicable and one of the main objectives of chemistry courses should be to train students to consistently use this approach.

  17. Free and open-source automated 3-D microscope.

    Science.gov (United States)

    Wijnen, Bas; Petersen, Emily E; Hunt, Emily J; Pearce, Joshua M

    2016-11-01

    Open-source technology not only has facilitated the expansion of the greater research community, but by lowering costs it has encouraged innovation and customizable design. The field of automated microscopy has continued to be a challenge in accessibility due the expense and inflexible, noninterchangeable stages. This paper presents a low-cost, open-source microscope 3-D stage. A RepRap 3-D printer was converted to an optical microscope equipped with a customized, 3-D printed holder for a USB microscope. Precision measurements were determined to have an average error of 10 μm at the maximum speed and 27 μm at the minimum recorded speed. Accuracy tests yielded an error of 0.15%. The machine is a true 3-D stage and thus able to operate with USB microscopes or conventional desktop microscopes. It is larger than all commercial alternatives, and is thus capable of high-depth images over unprecedented areas and complex geometries. The repeatability is below 2-D microscope stages, but testing shows that it is adequate for the majority of scientific applications. The open-source microscope stage costs less than 3-9% of the closest proprietary commercial stages. This extreme affordability vastly improves accessibility for 3-D microscopy throughout the world. © 2016 The Authors Journal of Microscopy © 2016 Royal Microscopical Society.

  18. Cluster secondary ion mass spectrometry microscope mode mass spectrometry imaging.

    Science.gov (United States)

    Kiss, András; Smith, Donald F; Jungmann, Julia H; Heeren, Ron M A

    2013-12-30

    Microscope mode imaging for secondary ion mass spectrometry is a technique with the promise of simultaneous high spatial resolution and high-speed imaging of biomolecules from complex surfaces. Technological developments such as new position-sensitive detectors, in combination with polyatomic primary ion sources, are required to exploit the full potential of microscope mode mass spectrometry imaging, i.e. to efficiently push the limits of ultra-high spatial resolution, sample throughput and sensitivity. In this work, a C60 primary source was combined with a commercial mass microscope for microscope mode secondary ion mass spectrometry imaging. The detector setup is a pixelated detector from the Medipix/Timepix family with high-voltage post-acceleration capabilities. The system's mass spectral and imaging performance is tested with various benchmark samples and thin tissue sections. The high secondary ion yield (with respect to 'traditional' monatomic primary ion sources) of the C60 primary ion source and the increased sensitivity of the high voltage detector setup improve microscope mode secondary ion mass spectrometry imaging. The analysis time and the signal-to-noise ratio are improved compared with other microscope mode imaging systems, all at high spatial resolution. We have demonstrated the unique capabilities of a C60 ion microscope with a Timepix detector for high spatial resolution microscope mode secondary ion mass spectrometry imaging. Copyright © 2013 John Wiley & Sons, Ltd.

  19. Remote Histology Learning from Static versus Dynamic Microscopic Images

    Science.gov (United States)

    Mione, Sylvia; Valcke, Martin; Cornelissen, Maria

    2016-01-01

    Histology is the study of microscopic structures in normal tissue sections. Curriculum redesign in medicine has led to a decrease in the use of optical microscopes during practical classes. Other imaging solutions have been implemented to facilitate remote learning. With advancements in imaging technologies, learning material can now be digitized.…

  20. An electron microscope for the aberration-corrected era

    International Nuclear Information System (INIS)

    Krivanek, O.L.; Corbin, G.J.; Dellby, N.; Elston, B.F.; Keyse, R.J.; Murfitt, M.F.; Own, C.S.; Szilagyi, Z.S.; Woodruff, J.W.

    2008-01-01

    Improved resolution made possible by aberration correction has greatly increased the demands on the performance of all parts of high-end electron microscopes. In order to meet these demands, we have designed and built an entirely new scanning transmission electron microscope (STEM). The microscope includes a flexible illumination system that allows the properties of its probe to be changed on-the-fly, a third-generation aberration corrector which corrects all geometric aberrations up to fifth order, an ultra-responsive yet stable five-axis sample stage, and a flexible configuration of optimized detectors. The microscope features many innovations, such as a modular column assembled from building blocks that can be stacked in almost any order, in situ storage and cleaning facilities for up to five samples, computer-controlled loading of samples into the column, and self-diagnosing electronics. The microscope construction is described, and examples of its capabilities are shown

  1. A color image processing pipeline for digital microscope

    Science.gov (United States)

    Liu, Yan; Liu, Peng; Zhuang, Zhefeng; Chen, Enguo; Yu, Feihong

    2012-10-01

    Digital microscope has found wide application in the field of biology, medicine et al. A digital microscope differs from traditional optical microscope in that there is no need to observe the sample through an eyepiece directly, because the optical image is projected directly on the CCD/CMOS camera. However, because of the imaging difference between human eye and sensor, color image processing pipeline is needed for the digital microscope electronic eyepiece to get obtain fine image. The color image pipeline for digital microscope, including the procedures that convert the RAW image data captured by sensor into real color image, is of great concern to the quality of microscopic image. The color pipeline for digital microscope is different from digital still cameras and video cameras because of the specific requirements of microscopic image, which should have the characters of high dynamic range, keeping the same color with the objects observed and a variety of image post-processing. In this paper, a new color image processing pipeline is proposed to satisfy the requirements of digital microscope image. The algorithm of each step in the color image processing pipeline is designed and optimized with the purpose of getting high quality image and accommodating diverse user preferences. With the proposed pipeline implemented on the digital microscope platform, the output color images meet the various analysis requirements of images in the medicine and biology fields very well. The major steps of color imaging pipeline proposed include: black level adjustment, defect pixels removing, noise reduction, linearization, white balance, RGB color correction, tone scale correction and gamma correction.

  2. Risk of osteoporosis in microscopic colitis.

    Science.gov (United States)

    Wildt, Signe; Munck, Lars K; Becker, Sabine; Brockstedt, Helle; Bonderup, Ole K; Hitz, Mette F

    2018-04-01

    Patients with microscopic colitis (MC) have several risk factors for osteoporosis. The prevalence of osteopenia and osteoporosis in MC is unknown. The primary purpose of this study was to evaluate bone mineral status in MC. Patients with MC and disease activity within the last 2 years were included. Bone turnover markers were analyzed and bone mineral density (BMD) was measured with Dual Energy X-ray Absorptiometry (DXA) at inclusion and after one year. Medical history, demographics, risk factors for osteoporosis, disease activity and treatment with cumulative budesonide dosage at least 3 years before inclusion was registered. Adrenal function was tested by adrenocortico-tropic hormone (ACTH) and an ACTH stimulation test at inclusion. Results were compared with age and sex-matched controls. Fifty MC patients (44 women) were included. Median age 67 (range 45-93); median disease duration 28 month (range 2-163); median cumulative budesonide dosage 702 mg (range 0-5400). No difference in number of patients with osteoporosis or osteopenia and BMD was detected between groups. The bone mineral formation marker specific alkaline phosphatase was lower in MC than controls 12 (5-69) µg/l versus 16 (10-35) µg/l (p <   0.005). Patients more often smoked (34% versus 10%, p = 0.001). Disease duration and cumulative budesonide dose was associated with lower BMD and T-score in hip (Spearman's rho; p < 0.05) with a cut of point of 2500 mg budesonide predicting osteopenia. Budesonide treatment did not affect adrenal gland function. The risk of osteoporosis in patients with MC is not increased. However, DXA scan is recommended in MC patients with known risk factors or active disease requiring longstanding budesonide treatment. Supplementation of calcium and vitamin-D in patients treated with budesonide is recommended.

  3. Microscopic colitis in children with chronic diarrhea.

    Science.gov (United States)

    Singh, Prashant; Das, Prasenjit; Jain, A K; Mathan, Minnie; Mathur, Meera; Bhat, Abdus Sami; Varma, Sharat; Chaturvedi, Mona K; Gupta, Siddhartha Datta; Bhatnagar, Shinjini

    2013-08-01

    The aim of the present study was to study microscopic colitis (MC) in children with special reference to its role in chronic diarrhea and changes in mucosal biopsies. A total of 100 consecutive children ages 3 to 12 years, with nonbloody diarrhea (passage of ≥3 loose stools per day) of >12 weeks' duration were screened and 26 were enrolled in the study in which no specific etiology could be found and colonoscopy did not reveal any mucosal abnormality. Colonic biopsies were evaluated for the presence of lymphocytic colitis or collagenous colitis and those with the characteristic changes were defined to have MC (group A). Colonic biopsies from patients with MC were compared with biopsies from patients with chronic diarrhea but no evidence of MC (group B). One hundred children ages 3 to 12 years with bleeding per rectum were screened and colonic biopsies from 45 patients (group C) who had colonic mucosal changes but no vascular or polyp lesion were compared with patients with MC. Of the 26 patients with chronic diarrhea, MC was found in 5 (3 lymphocytic colitis and 2 collagenous colitis). Significantly higher polymorphonuclear infiltration was seen in group A as compared with group B (13.8 [5.4-20.6] vs 7.2 [0-19.6]; P = 0.03) or group C (13.8 [5.4-20.6] vs 4 [0-13.4]; P = 0.007). Intraepithelial lymphocytes (12 [4-32] vs 4 [0-24]; P = 0.008) and basement membrane thickening (3.5 [2.9-10.6] vs 2.5 [1.6-5.86]; P = 0.008) were also significantly higher in group A as compared with group C. MC was found to be present in children with nonbloody chronic diarrhea in children. Further multicentric studies may provide adequate data on its prevalence.

  4. Dielectrophoretic spectroscopy using a microscopic electrode array

    Science.gov (United States)

    Kirmani, Syed Abdul Mannan; Gudagunti, Fleming Dackson; Velmanickam, Logeeshan; Nawarathna, Dharmakeerthi; Lima, Ivan T.

    2017-02-01

    Dielectrophoresis (DEP) is a commonly used technique in biomedical engineering to manipulate biomolecules. DEP is defined as the force acting on dielectric particles when they are exposed to non-uniform electric fields. DEP effect can be divided in three categories: positive (dielectric particles are attracted to the electrodes), negative, and zero force DEP. The cross-over frequency is the frequency in which the DEP force is equal to zero. The cross-over frequency depends on the conductivity and the permittivity of the particles and of the suspended medium. The DEP cross-over frequency has been utilized in detecting/quantifying biomolecules. A manual procedure is commonly used to estimate the cross-over frequency of biomolecules. Therefore, the accuracy of this detection method is significantly limited. To address this issue, we designed and tested an automated procedure to carry out DEP spectroscopy in dielectric particles dissolved in a biological buffer solution. Our method efficiently measures the effect of the DEP force through a live video feed from the microscope camera and performs real-time image processing. It records the change in the fluorescence emission as the system automatically scans the electric frequency of the function generator over a specified time interval. We demonstrated the effectiveness of the method by extracting the crossover frequencies and the DEP spectrum of polystyrene beads with blue color dye (1000 nm diameter) and green fluorescent polystyrene beads with 500 nm diameter using this procedure. This approach can lead to the development of a biosensor with significantly higher sensitivity than existing detection methods.

  5. Operation of a scanning near field optical microscope in reflection in combination with a scanning force microscope

    NARCIS (Netherlands)

    van Hulst, N.F.; Moers, M.H.P.; Moers, M.H.P.; Noordman, O.F.J.; Noordman, O.F.J.; Faulkner, T.; Segerink, Franciscus B.; van der Werf, Kees; de Grooth, B.G.; Bölger, B.; Bölger, B.

    1992-01-01

    Images obtained with a scanning near field optical microscope (SNOM) operating in reflection are presented. We have obtained the first results with a SiN tip as optical probe. The instrument is simultaneously operated as a scanning force microscope (SFM). Moreover, the instrument incorporates an

  6. Contamination of wheat grain with microscopic fungi and their metabolites in Poland in 2006-2009.

    Science.gov (United States)

    Stuper-Szablewska, Kinga; Perkowski, Juliusz

    2014-01-01

    Microscopic fungi are microorganisms commonly found in cereal products. Pathogens of cereals colonising kernels are responsible, among other things, for deterioration of the technological value of grain. However, the greatest threat is posed by mycotoxins produced by toxin-forming strains of these microorganisms. The aim of the present study was to determine the level of contamination with microscopic fungi and mycotoxins from the group of trichothecenes in wheat grain from Poland in a 4-year cycle. In the period 2006-2009, studies were conducted on the content of fungal metabolites (ergosterol [ERG] and type A and B trichothecenes) and the content of microscopic fungi expressed in colony-forming units (CFU) in wheat grain. A total of 129 grain samples were examined. Analysed wheat samples had similar contents of both the investigated fungal metabolites and levels of microscopic fungi. Contents of microscopic fungi were low. Concentration of ERG, on average, was 2.64 mg/kg, while in colony forming units this value ranged from 10(1) CFU/g to over 10(3) CFU/g. The total concentration of type A and B trichothecenes was also low and within the 4 years of the investigation did not exceed 0.062 mg/kg. Concentration of DON did not exceed 1,250 µg/kg, established as safe in grain for human consumption, in any of the tested samples. For the results collected in the years 2006-2009 and presented in this paper, correlations were calculated between the amount of mycoflora and analysed metabolites in 3 possible combinations: 0.7096 for ERG/total toxin concentration, 0.6086 for ERG/log CFU/g, and 0.4016 for the concentration of total toxins/log CFU/g. Highly significant correlations between the content of trichothecenes and the concentration of ERG indicate that the level of this metabolite is closely related to the content of mycotoxins in grain.

  7. Construction and test of the PRIOR proton microscope

    International Nuclear Information System (INIS)

    Lang, Philipp-Michael

    2015-01-01

    The study of High Energy Density Matter (HEDM) in the laboratory makes great demands on the diagnostics because these states can usually only be created for a short time and usual diagnostic techniques with visible light or X-rays come to their limit because of the high density. The high energy proton radiography technique that was developed in the 1990s at the Los Alamos National Laboratory is a very promising possibility to overcome those limits so that one can measure the density of HEDM with high spatial and time resolution. For this purpose the proton microscope PRIOR (Proton Radiography for FAIR) was set up at GSI, which not only reproduces the image, but also magnifies it by a factor of 4.2 and thereby penetrates matter with a density up to 20 g/cm 2 . Straightaway a spatial resolution of less than 30 μm and a time resolution on the nanosecond scale was achieved. This work describes details to the principle, design and construction of the proton microscope as well as first measurements and simulations of essential components like magnetic lenses, a collimator and a scintillator screen. For the latter one it was possible to show that plastic scintillators can be used as converter as an alternative to the slower but more radiation resistant crystals, so that it is possible to reach a time resolution of 10 ns. Moreover the characteristics were investigated for the system at the commissioning in April 2014. Also the changes in the magnetic field due to radiation damage were studied. Besides that an overview about future applications is given. First experiments with Warm Dense Matter created by using a Pulsed Power Setup have already been performed. Furthermore the promising concept of combining proton radiography with particle therapy has been investigated in context of the PaNTERA project. An outlook on the possibilities with future experiments at the FAIR accelerator facility is given as well. Because of higher beam intensity an energy one can expect even

  8. Design of an affordable fluorescence confocal laser scanning microscope for medical diagnostics

    Science.gov (United States)

    Bechtel, Christin; Knobbe, Jens; Grüger, Heinrich; Lakner, Hubert

    2012-12-01

    Confocal fluorescence microscopes are a promising imaging tool in medical diagnostics due to their capability to selectively survey cross-sections of individual layers from `thick' samples. Non-invasive depth resolved investigation of neoplastic skin disorders is one example among other applications. However these microscopes are at present uncommon in medical practice. This is due to their main application area in research. The instruments dealt with here are generally complex, stationary units and are accordingly cost-intensive. It is for this reason, that we have designed a robust and portable MEMS based confocal fluorescence microscope with a field of view of 0.6mm x 0.6mm. This has been made possible by the integration of a 2D micro scanner mirror developed at Fraunhofer IPMS. A variable acquisition depth of cross-sectional images of the fluorescence specimen is enabled by an integrated z-shifter. With the use of commercially available optics an optical demonstrator set up has been realized. To characterize and to demonstrate the ability of this system test measurements were performed. The resolution of the microscope is better than 228 lp/mm determined by 1951 USAF resolution test target. Images of various biological samples are presented and optical sectioning capabilities are shown. A comparison of the measured with the predicted system performance will be given.

  9. Spontaneous fission of superheavy nuclei in a macroscopic-microscopic model

    International Nuclear Information System (INIS)

    Lojewski, Z.

    2012-01-01

    A systematic study of spontaneous fission half-lives of superheavy nuclei in the framework of the macroscopic-microscopic method was performed. The macroscopic-microscopic calculations of the half-lives consist in determining the collective potential energy V which splits into microscopic and smooth average macroscopic parts as well as into a nucleus mass tensor of the nucleus undergoing the fission process. The microscopic part of the energy is calculated using the single-particle Woods-Saxon potential with a universal set of parameters. Two models of the residual pairing interaction were studied. In the first approach we used monopole pairing (with constant matrix elements G). In the second approximation the pairing matrix elements were calculated with ?-force and are state dependent. As the macroscopic part of collective energy we examined four different macroscopic models of nuclear energy: Myers - Swiatecki liquid drop, Droplet expansion, Yukawa-plus-Exponential and the Lublin-Strasbourg Drop model. The analysis covers a wide range of even-even superheavy nuclei from Z = 100 to Z = 126. The calculations of spontaneous fission half-lives were performed by means of a WKB approximation, in the multi-dimensional dynamical-programming method within parameters describe the shape of nuclei. The studies offer an opportunity of a comprehensive approach to a very interesting group of exotic heavier nuclei, which are currently investigated by experimenters

  10. Microscopic polyangiitis: Atypical presentation with extensive small bowel necrosis, diffuse alveolar hemorrhage, and renal failure

    Directory of Open Access Journals (Sweden)

    Justin M. Segraves, M.D.

    2017-01-01

    Full Text Available Microscopic polyangiitis is an uncommon systemic vasculitis of varying severity that is associated with myeloperoxidase (MPO and perinuclear antineutrophil cytoplasmic (p-ANCA antibodies. The most commonly affected organs are the lungs and kidneys. We report on a very unusual case of microscopic polyangiitis presenting with severe mesenteric ischemia in addition to diffuse alveolar hemorrhage and acute renal failure. The patient was initially diagnosed with acute pancreatitis at an outside facility given his severe abdominal pain and elevated pancreatic enzymes. Further investigations after transfer to our facility determined that the patient was actually suffering from a severe exacerbation of previously diagnosed microscopic polyangiitis. He quickly developed diffuse alveolar hemorrhage (DAH necessitating intubation and acute kidney injury (AKI requiring dialysis. He subsequently developed mesenteric ischemia and bowel necrosis resulting in emergent laparotomy and extensive small bowel resection. Physicians need to be aware that microscopic polyangiitis can very rarely present with severe involvement of the abdominal viscera and mesenteric vessels. Severe disease necessitates the use of high dose IV steroids, rituximab or cyclophosphamide, and plasma exchange (PLEX.

  11. Microscopic polyangiitis: Atypical presentation with extensive small bowel necrosis, diffuse alveolar hemorrhage, and renal failure.

    Science.gov (United States)

    Segraves, Justin M; Iyer, Vivek N

    2017-01-01

    Microscopic polyangiitis is an uncommon systemic vasculitis of varying severity that is associated with myeloperoxidase (MPO) and perinuclear antineutrophil cytoplasmic (p-ANCA) antibodies. The most commonly affected organs are the lungs and kidneys. We report on a very unusual case of microscopic polyangiitis presenting with severe mesenteric ischemia in addition to diffuse alveolar hemorrhage and acute renal failure. The patient was initially diagnosed with acute pancreatitis at an outside facility given his severe abdominal pain and elevated pancreatic enzymes. Further investigations after transfer to our facility determined that the patient was actually suffering from a severe exacerbation of previously diagnosed microscopic polyangiitis. He quickly developed diffuse alveolar hemorrhage (DAH) necessitating intubation and acute kidney injury (AKI) requiring dialysis. He subsequently developed mesenteric ischemia and bowel necrosis resulting in emergent laparotomy and extensive small bowel resection. Physicians need to be aware that microscopic polyangiitis can very rarely present with severe involvement of the abdominal viscera and mesenteric vessels. Severe disease necessitates the use of high dose IV steroids, rituximab or cyclophosphamide, and plasma exchange (PLEX).

  12. Macro-microscopic examination of leaves of Cinnamomum malabatrum (Burm. f.) Blume sold as Tamalapatra.

    Science.gov (United States)

    Sunil Kumar, K N

    2013-04-01

    Leaves of Cinnamomum tamala Nees & Eberm. (Lauraceae) commonly known as 'Tamalapatra' is a highly reputed commodity in drug and spice trade. Its adulteration with other leaf species belonging to genus Cinnamomum is found to be a common practice in India and other parts of the world. Thorough macroscopic and microscopic investigations are essential to differentiate them. Survey of South Indian crude drug markets revealed that in place of C. tamala some other leaves of Cinnamomum species are sold. Fresh leaves of various Cinnamomum species, including C. tamala, growing in south India were collected and studied to establish their correct identity. Leaves sold in markets of S. India under the name of Tamalapatra were subjected for detailed macro-microscopic evaluation including maceration and powder microscopy. Leaves of Cinnamomum malabatrum showed many distinguishing macro-microscopic characters, which will serve as markers to differentiate them from C. tamala the official source of Tamalapatra. Though macroscopy will serve the purpose of identification of the entire drug, microscopy had revealed the identity of the commercial substitute even in fragmented and powdered form. Macro-microscopic identity of C. malabatrum is established in comparison with the official drug, further chemical and biological studies may be confirmative in deciding the leaves as a substitute or adulterant.

  13. A compact combined ultrahigh vacuum scanning tunnelling microscope (UHV STM) and near-field optical microscope

    International Nuclear Information System (INIS)

    Woolley, R A J; Hayton, J A; Cavill, S; Ma, Jin; Beton, P H; Moriarty, P

    2008-01-01

    We have designed and constructed a hybrid scanning near-field optical microscope (SNOM)–scanning tunnelling microscope (STM) instrument which operates under ultrahigh vacuum (UHV) conditions. Indium tin oxide (ITO)-coated fibre-optic tips capable of high quality STM imaging and tunnelling spectroscopy are fabricated using a simple and reliable method which foregoes the electroless plating strategy previously employed by other groups. The fabrication process is reproducible, producing robust tips which may be exchanged under UHV conditions. We show that controlled contact with metal surfaces considerably enhances the STM imaging capabilities of fibre-optic tips. Light collection (from the cleaved back face of the ITO-coated fibre-optic tip) and optical alignment are facilitated by a simple two-lens arrangement where the in-vacuum collimation/collection lens may be adjusted using a slip-stick motor. A second in-air lens focuses the light (which emerges from the UHV system as a parallel beam) onto a cooled CCD spectrograph or photomultiplier tube. The application of the instrument to combined optical and electronic spectroscopy of Au and GaAs surfaces is discussed

  14. Comparison of Microscopic Drivers' Probabilistic Lane-changing Models With Real Traffic Microscopic Data

    Directory of Open Access Journals (Sweden)

    Seyyed Mohammad Sadat Hoseini

    2011-07-01

    Full Text Available The difficulties of microscopic-level simulation models to accurately reproduce real traffic phenomena stem not only from the complexity of calibration and validation operations, but also from the structural inadequacies of the sub-models themselves. Both of these drawbacks originate from the scant information available on real phenomena because of the difficulty in gathering accurate field data. This paper studies the traffic behaviour of individual drivers utilizing vehicle trajectory data extracted from digital images collected from freeways in Iran. These data are used to evaluate the four proposed microscopic traffic models. One of the models is based on the traffic regulations in Iran and the three others are probabilistic models that use a decision factor for calculating the probability of choosing a position on the freeway by a driver. The decision factors for three probabilistic models are increasing speed, decreasing risk of collision, and increasing speed combined with decreasing risk of collision. The models are simulated by a cellular automata simulator and compared with the real data. It is shown that the model based on driving regulations is not valid, but that other models appear useful for predicting the driver’s behaviour on freeway segments in Iran during noncongested conditions.

  15. Inverse Association Between Helicobacter pylori Gastritis and Microscopic Colitis.

    Science.gov (United States)

    Sonnenberg, Amnon; Genta, Robert M

    2016-01-01

    Inflammatory bowel disease is known to be inversely associated with Helicobacter pylori infection of the upper gastrointestinal tract. We hypothesized that a similar inverse association also applied to microscopic colitis. The associations between microscopic colitis and presence of H. pylori-positive chronic active gastritis (CAG), H. pylori-negative CAG, intestinal metaplasia, or gastric atrophy were expressed as odds ratios with their 95% confidence intervals. Multivariate logistic regression analyses were used to adjust these associations for sex, age, percentage residents per ZIP code with white, black, Hispanic, or Asian ethnicity, percentage with college education, average housing values, annual income, and population size of individual ZIP codes. H. pylori-positive CAG was less common among patients with than without microscopic colitis (odds ratio = 0.61; 95% confidence interval, 0.52-0.70). Intestinal metaplasia also occurred less frequently among patients with than without microscopic colitis (0.75, 0.65-0.86). These inverse associations remained unaffected by adjustments for parameters of ethnicity and socioeconomic status. In contradistinction with H. pylori-positive CAG, H. pylori-negative CAG was more common in patients with than without microscopic colitis (1.54, 1.17-1.97). H. pylori infection and microscopic colitis are inversely associated. This observation is consistent with similar inverse associations found between H. pylori and inflammatory bowel disease. These relationships may provide clues about the yet unknown etiology of microscopic colitis.

  16. Faraday rotation imaging microscope with microsecond pulse magnet

    Energy Technology Data Exchange (ETDEWEB)

    Suwa, Masayori, E-mail: msuwa@chem.sci.osaka-u.ac.jp [Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043 (Japan); Tsukahara, Satoshi [Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043 (Japan); Watarai, Hitoshi, E-mail: watarai@chem.sci.osaka-u.ac.jp [Institute for NanoScience Design, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531 (Japan)

    2015-11-01

    We have fabricated a high-performance Faraday rotation (FR) imaging microscope that uses a microsecond pulse magnet comprising an insulated gated bipolar transistor and a 2 μF capacitor. Our microscope produced images with greater stability and sensitivity than those of previous microscopes that used millisecond pulse magnet; these improvements are likely due to high repetition rate and negligible Joule heating effects. The mechanical vibrations in the magnet coil caused by the pulsed current were significantly reduced. The present FR microscope constructed an averaged image from 1000 FR images within 10 min under 1.7 T. Applications of the FR microscope to discriminating three benzene derivatives in micro-capillaries and oscillation-free imaging of spherical polystyrene and polymethyl methacrylate microparticles demonstrated its high performance. - Highlights: • A microsecond pulse magnet with high repetition rate of 10 Hz was fabricated. • Faraday rotation (FR) imaging microscope with the μs magnet was constructed. • Benzene derivatives in microcapillaries were distinguished with the FR microscope. • FR images of single polymer microspheres of 20 μm were correctly acquired. • Observed FR angles agreed quantitatively with those expected from Verdet constants.

  17. Ultrafast superresolution fluorescence imaging with spinning disk confocal microscope optics.

    Science.gov (United States)

    Hayashi, Shinichi; Okada, Yasushi

    2015-05-01

    Most current superresolution (SR) microscope techniques surpass the diffraction limit at the expense of temporal resolution, compromising their applications to live-cell imaging. Here we describe a new SR fluorescence microscope based on confocal microscope optics, which we name the spinning disk superresolution microscope (SDSRM). Theoretically, the SDSRM is equivalent to a structured illumination microscope (SIM) and achieves a spatial resolution of 120 nm, double that of the diffraction limit of wide-field fluorescence microscopy. However, the SDSRM is 10 times faster than a conventional SIM because SR signals are recovered by optical demodulation through the stripe pattern of the disk. Therefore a single SR image requires only a single averaged image through the rotating disk. On the basis of this theory, we modified a commercial spinning disk confocal microscope. The improved resolution around 120 nm was confirmed with biological samples. The rapid dynamics of micro-tubules, mitochondria, lysosomes, and endosomes were observed with temporal resolutions of 30-100 frames/s. Because our method requires only small optical modifications, it will enable an easy upgrade from an existing spinning disk confocal to a SR microscope for live-cell imaging. © 2015 Hayashi and Okada. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  18. A Microscopic Theory of the Neutron

    Science.gov (United States)

    Zheng-Johansson, J. X.

    2016-01-01

    A microscopic theory of the neutron, which consists in a neutron model constructed using key relevant experimental observations as input information and the first principles solutions for the basic properties of the model neutron, is proposed within a framework consistent with the Standard Model. The neutron is composed of an electron e and a proton p that are separated at a distance r1 of the order 10-18 m, and are in relative orbital angular motion and Thomas precession highly relativistically, with their reduced mass moving along a quantised circular orbit l = 1, j = ½ of radius vector r1½ = r1rˆ1½ about their mass centre. The associated rotational energy flux has a spin ½ and resembles a confined antineutrino. The particles e, p are attracted with one another predominantly by a central magnetic force produced as result of the particles’ relative precessional-orbital and intrinsic angular motions. The interaction force (resembling the weak force), potential (resembling the Higgs’ field), and a corresponding excitation Hamiltonian (HI), among others, are derived based directly on first principles laws of electromagnetism, quantum mechanics and relativistic mechanics within a unified framework. In particular, the equation for 4/3πr13HI, which is directly comparable with the Fermi constant GF, is predicted as GF = 4/3πr13HI = AoC0 ½/γeγp, where Ao = e2ℏ2/12π𝜖0m0em0pc2, m0em0p are the e, p rest masses, C0½ is a geo-magnetic factor, and γe, γp are the Lorentz factors. Quantitative solution for a stationary meta-stable neutron is found to exist at the extremal point r1m = 2.537 × 10-18 m, at which the GF is a minimum (whence the neutron lifetime is a maximum) and is equal to the experimental value. Solutions for the magnetic moment, effective spin (½), fine structure constant, and intermediate vector boson masses of the neutron are also given in this paper.

  19. Control circuit for a scanning tunneling microscope

    Science.gov (United States)

    Munoz, Raúl C.; Villagra, Paolo; Kremer, Germán; Moraga, Luis; Vidal, Guillermo

    1998-09-01

    We have successfully built and tested a circuit designed to control a piezoelectric tube scanner having the standard single inner-electrode quartered outer-electrode configuration, using digital-to-analog (D/A) converters commercially available. To avoid noise associated with the PC, the signals transmitted by the D/A channels to the control electronics are received by instrumentation amplifiers INA 105 at the control circuit, providing 86 dB common mode rejection, thereby over four orders of magnitude of immunity to common mode noise. To prevent ground loops in the communication between the control electronics and the analog-to-digital (A/D) converters, a novel approach was used. The signals sent by the control electronics to the A/D converters were transmitted via isolation amplifiers ISO 122 followed by a 10 kHz Sallen-Key low pass filter incorporated at each output of the control circuit, providing galvanic isolation between the control electronics and the PC, thereby eliminating ground loops. The control circuit was designed to allow analog as well as digital feedback, selectable via a toggle switch. The design also incorporates the possibility of using two independent external signals to modulate the polarization of the sample and two independent external signals to modulate the piezoelectric transducer drive along the Z direction. It also incorporates the possibility of electronically canceling the slope that might occur while scanning due to the sample being tilted along the X axis (fast scan direction) and/or along the Y axis (slow scan direction). The circuit was tested using two 12 bit A/D-D/A converters DAS 1602 to control the scanner of a scanning tunneling microscope, with a home-built scanning head, electrometer, and preamplifier. With the complete system in operation but in the absence of tunneling current, the electrometer exhibits a current noise under 3 pA rms and a response time of 30 μs to a step input current, a performance that compares well

  20. Effect of operating microscope light on brain temperature during craniotomy.

    Science.gov (United States)

    Gayatri, Parthasarathi; Menon, Girish G; Suneel, Puthuvassery R

    2013-07-01

    Operating microscopes used during neurosurgery are fitted with xenon light. Burn injuries have been reported because of xenon microscope lighting as the intensity of xenon light is 300 W. We designed this study to find out if the light of operating microscope causes an increase in temperature of the brain tissue, which is exposed underneath. Twenty-one adult patients scheduled for elective craniotomies were enrolled. Distal esophageal temperature (T Eso), brain temperature under the microscope light (T Brain), and brain temperature under dura mater (T Dura) were measured continuously at 15-minute intervals during microscope use. The irrigation fluid temperature, room temperature, intensity of the microscope light, and the distance of the microscope from the brain surface were kept constant. The average age of the patients was 44±15 years (18 males and 3 females). The mean duration of microscope use was 140±39 minutes. There were no significant changes in T Brain and T Dura and T Eso over time. T Dura was significantly lower than T Brain both at time 0 and 60 minutes but not at 90 minutes. T Brain was significantly lower than T Eso both at time 0 and 60 minutes but not at 90 minutes. The T Dura remained significantly lower than T Eso at 0, 60, and 90 minutes. Our study shows that there is no significant rise in brain temperature under xenon microscope light up to 120 minutes duration, at intensity of 60% to 70%, from a distance of 20 to 25 cm from the brain surface.